Sunlight and weather resistance are particularly good. Not afraid of refrigerants such as dichlorodifluoromethane and ammonia, resistant to dilute acid and grease-resistant lubricating oils, but with large swelling in mineral oils with low aniline point. It is easy to crystallize and harden at low temperatures. Applicable to a variety of contact with the atmosphere, sunlight, ozone environment and a variety of fire-resistant, chemical-resistant seals. It is not recommended for use in strong acids, nitrohydrocarbons, esters, chloroform, and ketones. The general operating temperature range is -55~120 °C.