silicone rubber washers for Auto parts/food grade silicone gaskets/White Silicone GasketMaterialNR, NBR, SBR, EPDM, IIR, CR, SILICONE, VITONHardness20~90 Shore APacking Inner-Plastic Bag; Outer ... of colors,or transparent. And any shapes, round, square, oval silicone washers are ok for providing.welcome to customize.Production workshop