Killark AF-500GG - Superior corrosive resistant ZA12 zinc alloy casted body and end coupling - A 40 mil Polyolefin exterior coating - Includes type "A" phenolic insulating bushing - PTFE synthetic fiber reinforced gasket with steel washer to help maintain a strong seal - Tinned braided copper ring - Rain, water and concretetight AF Coated Series Expansion fittings are for use with IMC or rigid conduit installations. The AF Coated Series adds additional corrosion resistance in applications where abnormal environmental conditions exist. This series still prevents damage of the electrical installations typically used in buildings and bridges by compensating linear movement due to temperature fluctuation or structural movement. This series provides maximum 4” conduit movement (2” in either direction).