... Most competitive price. 4.ROHS approved. Details about o ring color code: Materials Comply with ROHS, NBR, Silicone (VMQ), ... as your request.Tolerance Strictly upon international standard, no flash.Color Black, transparent, green, red, yellow, grey, purple, ... ODM are highly welcomed, V ring, D ring, X ring are all available.Our advantages:1. Strong QC ... BS o rings are all available. o ring color code