Top 6 Best Slam Balls

of November 2024
1
Best ChoiceBest Choice
Nordic Lifting Dead Weight Slam Ball for CrossFit - Textured SlamBall for Core
Nordic Lifting
Nordic Lifting
10
Exceptional
View on Amazon
2
Best ValueBest Value
Champion Sports Gel Filled Medicine Ball (Red 2lbs)
Champion Sports
Champion Sports
9.9
Exceptional
View on Amazon
3
Champion Sports Rhino Elite Medicine Ball (2 pounds), Yellow
Champion Sports
Champion Sports
9.8
Exceptional
View on Amazon
4
Champion Sports MBR1 Medicine Ball Tree Black, 14 Inch L X 11 Inch W X 52 Inch H
Champion Sports
Champion Sports
9.7
Exceptional
View on Amazon
5
Champion Sports Rhino Fitness Slam Ball (pack of 1)
Champion Sports
Champion Sports
9.6
Exceptional
View on Amazon
6
Champion Sports Exercise Medicine Balls, 6-7 lbs, Leather with No-Slip Grip -
Champion Sports
Champion Sports
9.5
Excellent
View on Amazon
7
Champion Sports PRX12 Rhino Promax Elite Slam Balls, 12 lb, Soft Shell with
Champion Sports
Champion Sports
9.4
Excellent
View on Amazon
8
Yes4All Wall Ball, Wall Balls for Exercise, Weighted Ball, Medicine Ball and
Yes4All
Yes4All
9.3
Excellent
View on Amazon
9
Yes4All 10 lbs Slam Ball for Strength, Power and Workout - Fitness Exercise
Yes4All
Yes4All
9.2
Excellent
View on Amazon
10
Yes4All Soft Weighted Toning Ball Knurl 5lb Pink
Yes4All
Yes4All
9.1
Excellent
View on Amazon
11
Yes4All Slam Ball, No-Bounce Ball for Exercise, Cross Training and Core
Yes4All
Yes4All
9.0
Excellent
View on Amazon
12
Yes4All Fitness Slam Medicine Ball Triangle 25lbs for exercise, strength, power
Yes4All
Yes4All
8.9
Very Good
View on Amazon
13
Champion Sports RPX12 Rhino Promax Slam Balls, 12 lb, Soft Shell with Non-Slip
Champion Sports
Champion Sports
8.8
Very Good
View on Amazon
14
Champion Sports Rhino Fitness Slam Ball, 10 Pounds,Black
Champion Sports
Champion Sports
8.7
Very Good
View on Amazon
15
Yes4All 15 lbs Slam Ball for Strength Workout  Slam Medicine Ball (15 lbs,
Yes4All
Yes4All
8.6
Very Good
View on Amazon
16
Yes4All Upgraded Version Durable Solid Slam Medicine Balls from 10-40lbs,
Yes4All
Yes4All
8.5
Good
View on Amazon
17
BalanceFrom Workout Exercise Fitness Weighted Slam Ball, 20 lbs
BalanceFrom
BalanceFrom
8.4
Good
View on Amazon
18
Rage Fitness Slam Ball, Ideal for Cross Training, Core Exercises, Plyometric
Rage Fitness
Rage Fitness
8.3
Good
View on Amazon
19
ProsourceFit Slam Medicine Balls 20 lbs Smooth Textured Grip Dead Weight Balls
ProsourceFit
ProsourceFit
8.2
Good
View on Amazon
20
SPRI Dead Weight Slam Ball - Durable Sand-Filled No-Bounce Heavy Duty Ball for
SPRI
SPRI
8.1
Good
View on Amazon
21
Weighted Slam Ball by Day 1 Fitness  15 lbs RED - No Bounce Medicine Ball - Gym
Day 1 Fitness
Day 1 Fitness
8.0
Good
View on Amazon
22
JFIT Wall Ball, Red/Black, 15 LB
JFIT
JFIT
7.9
Good
View on Amazon

About Slam Balls

Click here to learn more about these products.

Nordic Lifting Dead Weight Slam Ball for CrossFit - Textured SlamBall for Core & Fitness Training 40 lb

SLAM BALL THAT ABSORBS HIGH IMPACT - Its Durable Structure is Built to Withstand Repeated Throwing. BURST-PROOF DESIGN - Our Slam Balls Have Thicker Shells Than Others, Drop-Tested and Can Take a Hit Without Blowing Out. TEXTURED SURFACE FOR EASY GRIP - Provides Strong Grip Even With Sweaty Hands. DOES NOT BOUNCE - Looking for a Basket Ball or a Slam Ball Choose Wisely, Cheaper Balls Will Bounce. INCLUDED - 1x Nordic Lifting Slam Ball, Exercise Guide, and 1 Year Manufacturers Warranty. VERSATILE TRAINING TOOL - Ideal for strength training, powerlifting, conditioning, and functional fitness workouts. Catering to athletes, fitness enthusiasts, and individuals seeking an effective full-body workout. With a wide range of slam ball exercises available, including slams, throws, squats, lunges, and rotational movements, users can customize their workouts to target specific muscle groups, improve athletic performance, and breakthrough fitness plateaus..

Champion Sports Gel Filled Medicine Ball (Red 2lbs)

Soft, pliable exterior for easy throwing and catching. Exceptional bounce designed for cardio training with a partner or use with a rebounder. Roto molded vinyl shell offers exceptional durability.

Champion Sports Rhino Elite Medicine Ball (2 pounds), Yellow

Synthetic rubber construction allows for a consistent bounce and durability. Use a medicine ball for core and muscle strengthening, flexibility, agility, and more. Exclusive textured surface and design ensures superior grip and handling. Weight 2 lb. Diameter 8 in.

Champion Sports MBR1 Medicine Ball Tree Black, 14 Inch L X 11 Inch W X 52 Inch H

ORGANIZE AND PROTECT YOUR GEAR Exercise Medicine balls are not cheap, so you want to keep them stored securely when not in use. The Champion Sports tree offers a practical solution to holding your workout balls in a safe and attractive fashion. 5-LEVELS, MULTIPLE WIDTHS Our ball stands feature 5 racks that increase in width as you go down a level. Spanning between 6- 8 in width, this workout equipment stand can accommodate medicine balls up to 11 in diameter and of varying weights. DURABLE BUILD Each medicine ball tree is made of unyielding steel tubing that can be subject to significant weight-bearing and wont topple over or break.. SLEEK, COMPACT DESIGN With shelves on only one side, the Champion Sports tree can be placed against a wall, out of the way of gym-goers and workout machines. The slim line design also offers a space-saving solution for displaying medicine balls. MORE THAN A MEDICINE BALL TREE While our display stand was designed for storing a medicine ball set, the pegs allow it to accommodate other workout gear and supplies such as holding other weighted balls or hanging jump ropes and exercise bands.

Champion Sports Rhino Fitness Slam Ball (pack of 1)

Features rubber treaded surface for superior grip. Ultra-durable design to withstand the most heavy of use. Versatile bounce resistant construction. Sand filled. 6 pound weight.

Champion Sports Exercise Medicine Balls, 6-7 lbs, Leather with No-Slip Grip - Weighted Med Ball Set for Weight Training, Stability, Plyometrics, Cross Training, Core Strength - Heavy Workout Ball

ELEVATE YOUR ROUTINE Champion Sports provides workout gear that makes your fitness goals as enjoyable, convenient, and achievable as possible. Our leather medicine balls are no exception - blending unwavering performance with attractive aesthetics. NON-SLIP, CONTROLLED GRIP The exterior is made of synthetic leather that lends itself to a supple texture but is still easy to hold - even when sweaty. Maintaining a steady grip is simple whether doing floor exercises, weight lifting, or aerobics. UNRIVALED, LASTING DURABILITY Using professional-grade, high-quality materials, our weighted ball will hold up to every throw, slam, or lift you put it through. Premium, reinforced stitching further promises long lasting functionality. MADE FOR A VARIETY OF EXERCISE The Champion Sports multi-purpose medicine ball set was created to be used by fitness experts and beginners. Our gym accessories can be used in a variety of classes including pilates, yoga, aerobics, or cross training. MIX AND MATCH This medicine ball collection offers an array of sizes, colors, and weights so you can continually mix up your exercise routine, adding challenge and variety when youre feeling bored and stagnant or going light on low-energy days.

Champion Sports PRX12 Rhino Promax Elite Slam Balls, 12 lb, Soft Shell with Non-Slip Grip, Medicine Wall Exercise Ball for Weightlifting, Plyometrics, Cross Training, & Home Gym Fitness

MIX UP YOUR ROUTINE The Rhino Promax slamball offers a fun and unique way to get an effective workout without using traditional gym equipment. Incorporate our jumbo slam balls into your workout to improve speed, agility, cardio and core strength.. SMOOTH, SUPERIOR GRIP Brandishing our proprietary Rhino Skin tacky vinyl exterior, users experience a comfortable yet controlled, non-slip grip. The exercise balls large, ergonomic build makes it easy to throw, catch, and slam - even when sweaty.. UNRIVALED STRENGTH AND PERFORMANCE Offering more give and bounce than typical medicine fitness balls, our slam ball was built for significant wear-and-tear and extreme surface contact. Its durability will hold up to every slam, throw, or maneuver.. FULL BODY WORKOUT Slam wall balls challenge main muscle groups as well as smaller, stabilizing ones. Adding these heavy balls to aerobic activity, weightlifting, cross training, or exercise classes ensures a full-body workout from head-to-toe.. Product use through repeated impact on rough surfaces or slamming it on the ground from overhead voids the coverage. Covered by U.S. Des. Pat. 718,825, sold under license from Exemplar Design LLC.

Yes4All Wall Ball, Wall Balls for Exercise, Weighted Ball, Medicine Ball and Full Body Dynamic Exercises, 6lbs - 30lbs

PACKAGE INCLUDES WALL BALL A TARGET STICKER Included a standard 12 75 diameter for a consistent feel across all weights The free wall ball target sticker included can be easily attached to any surface and once removed do not leave marks on the wall.. FIRM GRIP WITH FINGER LOOPS Non slip Cover Soft textured PVC cover for secure wall ball handling, especially during intensity workouts With finger loops on both sides and quality cover, leather medicine ball ensures non slip hold, even with sweaty hands. DURABLE STURDY WALL BALLS OVERTIME With durable synthetic leather high density iron sand construction, this weighted exercise ball is ideal choice for strength training Strong weight ball can withstand heavy impacts without deformation. SECURE WITH HEAVY DOUBLE STITCHES Strongly sewn seams of wall med ball ensure soft cotton layer remains fixed inside keeps iron sand from leaking Durable stitching makes this soft wall medicine ball ideal for drill training, enduring repeated use. VERSATILE WEIGHT OPTIONS Our wall medicine balls, ranging from 6 to 30lbs, are suitable for multi targets exercises, also including 10lb, 15lb, 20lb wall ball set Whether you choose small medicine ball or heavy ball, it's ideal for men women to increase speed, strength coordination.

Yes4All 10 lbs Slam Ball for Strength, Power and Workout - Fitness Exercise Ball with Grip Tread & Durable Rubber Shell (10 Lbs, Orange), Orange beast, 10lbs

CONSISTENT SHAPE AND BALANCE PVC soft slam balls for exercise offer balanced and stable workouts Whether slammed, tossed, or grabbed, a threaded slam ball keeps its shape. EASY TO GRIP WEIGHT BALL The textured surface of slam medicine balls for exercise offer a stable hold for overhead smashes, chest passes, and Russian twists Big slam ball prevents slips or drops. HIGH DENSITY SECURE FITNESS MEDICINE BALL This med slam ball filled with sand to prevent bouncing or rolling, enhance balance firmness of the ball. VARIOUS WEIGHT OPTIONS Mid size medicine ball leg raise is available in options of 10, 15, 20, 25, 30, and 40 lbs Strength training medicine balls cater to many fitness levels. FULL-BODY WORKOUT High-density slam balls for men are designed for wall slams, squats, or other power movements Slam balls for exercise baseball support various exercises to enhance overall fitness.

Yes4All Soft Weighted Toning Ball Knurl 5lb Pink

BUILD STRENGTH, BALANCE COORDINATION Toning Exercise Balls are ideal for balance, flexibility strength workouts. Performing exercises with this small weight ball engages your bodys deepest stabilizing muscles for coordination maximized strength. PVC SHELL UNSTABLE IRON SAND INSIDE Made of PVC and filled with iron sand, our weighted balls for exercise are durable to function well for a lifetime. Iron sand inside creates instability to activate different muscle groups for a leaner tighter body. COMPACT AND PORTABLE Take this small exercise ball or hand exercise ball on your travels for a quick workout. Keep it at the office to stretch and warm up your muscles with a weighted ball during breaks or after a long day at your desk.. MAKE SURE TO CHOOSE THE APPROPRIATE WEIGHT Please check these hand exercise balls s size carefully to see whether it fits your hands or not before purchase for the larger size, you might need to hold it with both hands.. VERSATILE WEIGHT OPTIONS Our collection of weighted exercise balls, similar to med balls, ranges from 2lbs to 10lbs. Choose the suitable workout ball or soft medicine ball set for your level and purpose. Tip Avoid placing the weighted ball on furniture with ethylene to prevent damage..

Yes4All Slam Ball, No-Bounce Ball for Exercise, Cross Training and Core Strength Workout 10lbs - Triangle Black

STRONG CONSTRUCTION Constructed of durable PVC material, Yes4All Slam Balls are designed to withstand intensive repetitive exercises for a long time With a heavy-duty textured shell, our medicine balls for exercise offer non slip stable grip for secure workout experience. HIGH DENSITY SECURE FITNESS MEDICINE BALL This med slam ball is filled with sand to prevent from bouncing or rolling, enhance balance firmness of the ball Seamless construction ensures durability safety during wall slams, squats or other power movements. EASY TO GRIP SURFACE Yes4All Slam Ball features a grooved and textured PVC shell to help you get a firm grip on the ball even with sweaty hands. TOTAL BODY WORKOUT Yes4All Slam Balls are ideal for workouts, as they help burn calories and strengthen your core muscles at the same time Weighted balls for exercise - essential fitness item for total body workouts, core strengthening, sports training, and coordination improvement. VARIOUS WEIGHT AND SIZE OPTIONS Available in weight options of 10, 15, 20, 25, 30, 40 lbs. Our slam balls for exercise feature 9.5 diameter shell, making it a suitable gym medicine ball for many fitness level.

Yes4All Fitness Slam Medicine Ball Triangle 25lbs for exercise, strength, power workout | Workout ball | Weighted ball | Exercise ball | Trendy Teal cycber monday deal

DESIGNED OUTER SHELL FOR BETTER GRIP Have a tight and easy grip with Yes4All slam ball Grooved and textured PVC shell offers non-slip grips during intense workout, enabling effective exercises and workouts even with sweaty hands. SAND THAT KEEPS THE BALL IN PLACE Sand filled exercise ball is designed to be less bouncy and is not likely to roll away once it touches the ground Then, picking it up and keeping it balanced while slamming also add extra challenges to your muscles. ABILITY TO ABSORB GREAT IMPACTS Durable slam ball with PVC shell and sand filled inside can withstand extreme energy from slamming activities Lets focus on your training and no more worrying about it breaking or being deformed. TRENDY COLOR SUITS EVERYONE Our newest slam medicine ball is now up for grabs with the modern color of Teal that looks even cooler. Anyone from teens to adults can find this newcomer attractive and it will make an elegant addition to their home gym. AVAILABLE IN A WIDE RANGE OF WEIGHT Choose the most suitable ones with our collection of slam balls that are available from 4.5 18kg Have the right one that keeps you practicing everyday for better body and better health.

Champion Sports RPX12 Rhino Promax Slam Balls, 12 lb, Soft Shell with Non-Slip Grip, Medicine Wall Exercise Ball for Weightlifting, Plyometrics, Cross Training, & Home Gym Fitness

MIX UP YOUR ROUTINE The Rhino Promax slamball offers a fun and unique way to get an effective workout without using traditional gym equipment. Incorporate our jumbo slam balls into your workout to improve speed, agility, cardio and core strength.. SMOOTH, SUPERIOR GRIP Brandishing our proprietary Rhino Skin leather shell, users experience a comfortable yet controlled, non-slip grip. The exercise balls large, ergonomic build makes it easy to throw, catch, and slam - even when sweaty.. UNRIVALED STRENGTH AND PERFORMANCE Offering more give and bounce than typical medicine fitness balls, our slam ball was built for significant wear-and-tear and extreme surface contact. Its durability will hold up to every slam, throw, or maneuver.. FULL BODY WORKOUT Slam wall balls challenge main muscle groups as well as smaller, stabilizing ones. Adding these heavy balls to aerobic activity, weight training, or exercise classes ensures a full-body workout from head-to-toe.. MIX AND MATCH This weighted slamming ball collection offers a variety of weights and colors so you can continually mix up your exercise routine - adding challenge and variety when youre feeling bored and stagnant or going light on low-energy days..

Champion Sports Rhino Fitness Slam Ball, 10 Pounds,Black

Features rubber treaded surface for superior grip. Ultra-durable design to withstand the most heavy of use. Versatile bounce resistant construction. Sand filled. 10 pound weight.

Yes4All 15 lbs Slam Ball for Strength Workout Slam Medicine Ball (15 lbs, Black)

HIGH-DENSITY MEDICINE EXERCISE BALL The Weight Ball is filled with sand to prevent it from bouncing or rolling and enhance the balance and firmness of the ball. EASY TO GRIP SURFACE Feature a grooved and textured PVC shell to help you get a firm grip on the ball even with sweaty hands. THICK SEAMLESS DESIGN Specially formulated resilient soft shell which is rotationally molded for a seamless construction to add more durability and ensure it cannot be split over time of use. BOOST YOUR AEROBIC CAPACITY Improve muscle mass, increase your heart rate burn more calories, enhance coordination between your hands eyes for smooth movements in sports. IDEAL FOR THE TOUGHEST WODS Non bounce, specifically designed for exercises, conditioning workouts, wood chops, overhead throws, twists, MMA, wrestling, football, basketball, or general athletic training.

Yes4All Upgraded Version Durable Solid Slam Medicine Balls from 10-40lbs, multicolor options (10 Lbs, Black)

HIGH-DENSITY MEDICINE EXERCISE BALL The Weight Ball is filled with iron sand to prevent it from bouncing or rolling and enhance the balance, Improve the gravity of the product and firmness of the ball. RECYCLED RUBBER MATERIAL Yes4All Slam Ball is made from recycled rubber to reduce the smell. We also bring out a new logo added on it. TEXTURED SURFACE Yes4All Weight Ball features a grooved and textured PVC shell to help you get a firm grip on the ball even with sweaty hands. THICK SEAMLESS DESIGN Specially formulated resilient soft shell which is rotationally molded for a seamless construction to add more durability and ensure it cannot be split over time of use. BOOST YOUR AEROBIC CAPACITY Medicine Exercise Ball Workout can help you improve muscle mass, increase your heart rate burn more calories, and enhance coordination between your hands eyes for smooth movements in sports. NON BOUNCE DESIGN Specifically designed for exercises, conditioning workouts, wood chops, overhead throws, twists, MMA, wrestling, football, basketball, or general athletic training.

BalanceFrom Workout Exercise Fitness Weighted Slam Ball, 20 lbs

Medicine Ball - Made with durable rubber and dual-texture, medicine ball workout helps develop core strength, improve coordination, etc.. Slam Ball - Rugged, textured surface  promotes a secure, easy grip, slam Ball workout builds strength, cardio and explosive power. Wall Ball - High quality synthetic-leather material on outside and tight double-stitching. Wall ball workout develops core and muscle strength. Wide Selections - All medicine balls, slam balls and wall balls come with wide selections. Choose the weights of your preference. Happiness - All genuine BalanceFrom products are covered by a 100 BalanceFrom satisfaction support. Sport Type Baseball.

Rage Fitness Slam Ball, Ideal for Cross Training, Core Exercises, Plyometric and Cardio Workouts, black (CF-SB310)

RAGE SLAM BALL is encased in an ultra-durable heavy-duty rubber shell It is high endurance impact approved and performs in ways a medicine ball cannot. AVAILABLE IN 7 SIZES - 10lb 15lb 20lb 25lb 30lb 35lb 40lb SOLD INDIVIDUALLY. TEXTURED SURFACE - Allows for a high quality grip even when wet. NO BOUNCE DESIGN - Ideal for various throwing and Slamming routines equipped with an air valve that releases pressure to prevent bursting. EQUIPPED WITH AIR VALVE - Releases pressure to prevent bursting This air valve also makes it possible to adjust the air capacity and overall firmness of the slam ball.

ProsourceFit Slam Medicine Balls 20 lbs Smooth Textured Grip Dead Weight Balls for Cross Training, Strength and Conditioning Exercises, Cardio and Core Workouts, Black

TEXTURED GRIP - A robust tire tread surface gives you a sturdy grip during intense workouts to prevent the heavy gym ball from slipping through your hands. DURABLE A supple rubber shell absorbs impact and holds up through the toughest workouts so you can slam your way to a more fit body. FULL BODY CONDITIONING From powerful throws to basics like squats presses, weighted medicine balls help improve coordination, core strength endurance. NO BOUNCING Dead weight design is perfect for forceful slams without the heavy medicine ball bouncing back or rolling for better control and safety. MULTIPURPOSE Available from 5 to 50 lbs, gym slam balls are ideal for Strength Training, Weight training, and Improving coordination.

SPRI Dead Weight Slam Ball - Durable Sand-Filled No-Bounce Heavy Duty Ball for Tossing, Slamming, Core Strength Training, Endurance, and General Fitness - Easy to Read Weight Label - 15 lb

CLASSIC SLAM BALL The SPRI weighted workout ball is a multi-use body training tool that can help develop muscular strength, endurance, power, stability, and joint integrity. Slam balls are ideal for tossing and slamming to work your core.. DURABLE MATERIAL This thick-walled gym ball is designed for durability with a heavy-duty rubber shell. The sand-filled no-bounce ball is ideal for tossing and slamming repeatedly to help work out your muscles.. STRENGTH TRAINING Our slam ball is an ideal multi-use fitness tool to complement your existing strength training equipment as slam balls can help to build endurance, tone muscles, and add resistance to your existing workout routine.. BUILT FOR REPEATED USE SPRI slam balls are great for daily use while keeping up with intense workouts for professional athletes. Whether at your at home gym or in fitness classes, these weight balls for exercise can be used in a variety of routines.. EASY TO READ WEIGHT LABEL The weighted balls are easy to read with weight stamps for quick identification of weight desired. The weighted exercise ball is available in 15lb, 20lb, and 30lb..

Weighted Slam Ball by Day 1 Fitness 15 lbs RED - No Bounce Medicine Ball - Gym Equipment Accessories for High Intensity Exercise, Functional Strength Training, Cardio

BUILT TO ENDURE THE TOUGHEST SLAMS With a thick outer shell that absorbs multiple impacts, slamming or throwing this handheld ball against walls or the ground forces you to utilize more energy and force, resulting in more calorie burning and endurance. EXPAND AND INTENSIFY YOUR WORKOUT PROGRAM Using these weighted workout balls in place of dumbbells or kettlebells can improve your training significantly and burn more calories by adding extra weight to your sit ups, push ups, squats, and plyo jumps. PERFECT FOR ANY STAGE OF FITNESS Whether youre a beginner on the fitness journey or a seasoned athlete, the weight varieties of these slam balls allow you to slowly and incrementally challenge yourself and provides an assortment of sizes for variety. LOOK LEANER AND STRONGER Improve your overall body muscle mass, cardiovascular endurance, and hand-eye coordination. Run longer, jump farther, lift more and perform better. Achieve your best shape, whether training alone or with a partner. STURDY CONSTRUCTION Comprised of a strong outer shell and a sand-filled core, the dead weight provides challenging resistance, but wont damage or hurt walls, floors, or your personal trainers hands. Our premium slam balls will last you ages.

JFIT Wall Ball, Red/Black, 15 LB

FUNCTIONAL TRAINING Not intended for slamming exercise, this extremely versatile, premium JFIT Soft Wall Ball can be used for multiple workout goals, with use in strength training and plyometric exercises, burpees, crunches, and beyond. DURABLE CONSTRUCTION Premium heavy-duty vinyl coated shell, has been laser cut, double stitched, and hand stuffed to maintain balance and keep shape, while featuring a non-slip grip making it easy to hold during your sweat session. MULTI-PURPOSE TOOL Use this quality wall ball for more than just your workout by stretching and rolling out tight and sore muscle fibers using your weight and gravity against the surface area of the ball to release tension. IMPROVE ENDURANCE Excellent for men and women looking to increase core strength, improve stabilization, and muscle density, press through your next wall squat while maintaining a steady grip during your exercise routine. PERFECT SIZE All sizes have a 14 diameter, except the 4LB ball which has a 9 diameter, allowing you to add variety and challenge yourself with our premium wall balls that are balance tested, with even weight distribution.
Disclaimer