... approved.. 4. Small quantity accepted. Details about product: 1. Materials: silicone rubber o-ring for toys, also can be NBR, EPDM ... weather resistant, good insulation property, anti-toxic, good air-permeable silicone rubber o-ring for toys, etc.4. Hardness: 20-80 ... strictly upon international standard, and no flash.7. Color: black silicone rubber o-ring for toys, transparent, green, red, yellow, grey ...