Silicone Rubber Breathing Mask: We use carious kind of polymers like NBR, NR, SBR Silicone, Neoprene etc Silicone Rubber ... , Neoprene or Custom Size According to the 2D or 3D technical drawing or samples Color transparent,black,any color Duro 30~80 ... , small error Finish Applications: Mechanically protects against the sharp edges of drilled or punched holes for wiring, cable, tuning, piping, hoses ...