nbr o-ring 1.Oil proof. 2.Heat resistant. 3.Standard size in stock. 4.Professional rubber manufacturer. nbr o-ring: 1. Materials: comply to ROHS, NBR, or Silicone (VMQ), EPDM, Viton, etc.2. Temperature: -40~120°C. 3. Hardness: 20 to 90 shore A or as your request. 4. Tolerance: strictly upon international standard, no flash.5. Color: black, transparent, green, red, yellow, grey, purple, pink or as ...