1. Material: Silicone
2. Purpose: Muscle anti-loose massage
3. Size: The diameter of the ball is about 7cm, and the peanut ball is about 14x7cm
4. Weight: About 150g for the smooth round ball, 405g for the smooth peanut ball, about 142g for the basketball pattern round ball, and 319g for the basketball pattern peanut ball
5. Features: grip exercise, Comfortable hand feeling, compact and easy to carry, exquisite texture, moderate hardness, training massage