1. Material: silicone2. Purpose: grip training, etc.3. The convex point grip relaxes the muscles, and the flat grip enhances the grip strength4. Soft hand feel, instantly rebound5. The wire diameter is thickened, and the elasticity is abundant6. After holding to the limit, pause for a while and slowly relax, the cycle repeats7. Comfortably fit hand muscles, non-slip design8. Size: 8x8x2 cm9. Weight: 64 grams

http://olla.gr/adjustable-strength-silicone-gripper-arm-muscle-strength-rehabilitation-training-fitness-equipment-colour-40-50lbblue/