- 1. HONEYCOMB EXPLOSION-PROOF TECHNOLOGY: avoid sports injuries, puncture by sharp objects, slowly vent air, and will not burst.2. ZERO PRESSURE REBOUND, THICKENED BALL WALL: The ball has no pressure memory rebound, evenly distributes the pressure, and avoids sports injuries.3. MATERIAL ENVIRONMENTAL PROTECTION: environmentally friendly PVC is odorless, durable, non-toxic and environmentally friendly