... weather resistant, good insulation property, anti-toxic, good air-permeable silicone rubber o-ring for toys, etc.4. Hardness: 20-80 shore ... : strictly upon international standard, and no flash.7. Color: black silicone rubber o-ring for toys, transparent, green, red, yellow, grey, ... 11 sets, from 50 tons to 300tons.4. Secondary vulcanization oven: 2 sets.5. Production capacity: 5000,000pcs.6. High ...