1-3mm Thick Black NBR Rubber Flat Round Ring Washer Seal Gaskets 9mm - 56.5mm OD
Material: NBR rubber. Made of nitrile rubber, which has a better temperature range than natural rubber. 5 x 9 x 1.4 mm for pipe fittings with 1/8" thread. 8 x 16 x 3 mm for tube fittings with 3/8" thread.