... Details about product: 1. Materials: silicone rubber o-ring for toys, also can be NBR, EPDM, Viton, etc ... anti-toxic, good air-permeable silicone rubber o-ring for toys, etc.4. Hardness: 20-80 shore ... and no flash.7. Color: black silicone rubber o-ring for toys, transparent, green, red, yellow, grey, purple, ... standard sizes are in ready stock.2. No tool cost, competitive price.3. Quick response for all ...