HIGH-DENSITY Strength 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,Brand quality - made from an extra thick and durable material. The non slip rubber surface ensures a firm hold even with rapid/Dynamic ranges of motion (power, endurance training) during exercise.,BOOST YOUR AEROBIC CAPACITY: Strength 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,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.