KEZE 400 Pcs Hydraulic O-Ring Made Material:Rubber o-rings set made of high-quality commercial grade black flexible nitrile(NBR) 70 Duro material,it has excellent high temperature and low temperature resistance,the working temperature range is from -40℃/-40℉ to 120℃/248℉,maintains good elasticity,has It has the advantages of ozone resist oil and heat KEZE 32 Size 1540 Pcs Rubber O Rings Assortment Kit WIDE APPLICATION:Assorted O-ring kit for faucets plumbing, pressure washer,hose nozzles,sinks,auto engines,machinery bearings, pumps,boats,oils,gas control valve,spray,air,kitchen bathroom water fitting seal leak repair