SB-20 Features: Add a bit of cardio to your strength workout while releasing stress or an excess amount of energy. Take the ball with both hands like you would grip a basketball, raise it above your head and slam it to the ground. Hence the name -Inch Slam Ball-Inch. Enjoy your energy releasing workout. Textured surface for better grip. Dense wall to prevent blow outs while slamming ball to the ground. Large easy to recognize weight value.