... size in stock. 4.Professional rubber manufacturer. nbr 70 o-ring: 1. Materials: comply to ROHS, NBR, or Silicone (VMQ), EPDM, Viton, etc ... . 4. Tolerance: strictly upon international standard, no flash.5. Color: black, transparent, green, red, yellow, grey, purple, pink or as your ... , AS568, JS, Metric and BS o rings are all available. nbr 70 o-ring