NBR nitrile rubber sealing ring: suitable for oil hydraulic oils, glycol, hydraulic oils, diester lubricants, silicone oil, Silicon grease, gasoline, water and other media. Is currently the most widely used and costs a minimum of rubber seals. Does not apply to polar solvents, such as ketones hydrocarbons, ozone, Nitro, MEK and chloroform. General operational temperature range is-40~120℃. Second, HNBR HNBR sealing ring: has excellent corrosion resistance, resistance to tearing and compression characteristics, resistance to ozone, sunlight and good weather. A better abrasion resistance than nitrile rubber. Suitable for washing machine, automobile engine systems and use of new environmentally friendly refrigerant R134a refrigerant in the system. Not recommended in alcohols, esters or aromatic solutions. General operational temperature range is-40~150℃.