Yes4All Slam Ball Medicine Ball - Easy Grip Textured Surface and Ultra Durable Rubber Shell - Weight Available 10, 15, 20 lbs HIGH-DENSITY CONSTRUCTION: Filled with iron sand to prevent the ball 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 CrossFit exercises, conditioning workouts, wood chops, overhead throws, twists, MMA, wrestling, football, basketball, or general athletic training Improve muscle mass, power, strength, and speed Increase heart rate and burn more calories Enhance overall balance, coordination between hands &amp; eyes Work best for triceps, abdomen, shoulders, calves, back, glutens, quads, etc.