CR: have good resistance of combustion, weather aging,  heat and good self-complementary property.
NBR: have good properties of oil resistance, abrasive resistance, weather aging resistance and hith temperature resistance.
EPDM: have good weather aging resistance, ozone resistace, polar liquid resistance and waterproof.
SBR: have good performance in wear resistance. it's wether aging resistant is superior than Natural Rubber. Apply to the material for rubber gaskets.