These bushings are designed for transformer, switchgear, entrance, and special power apparatus applications. The electrical ratings given are based on use in a liquid filled transformer with the lower end of the bushing under oil. Bushings are fully oil and watertight both at the top terminal and the mounting flange. Porcelain is gray glazed all over and the top skirts are designed for outdoor application. Flanges and washers are non-magnetic. Constant gasket pressure to top terminal is maintained by a dise spring to compensate for the thermal expansion and contraction of the copper stud. Nitrile (Buna-N) gasket is standard. For ordering assemblies with the cork-rubber composition gaskets, add the suffix “C” to the part number.