Appleton UNILETS UNF Union, Trade Size: 4 IN, Outside Diameter: 6.44 IN, Length: 3-1/2 IN, Flexibility: Rigid And IMC, Material: Malleable Iron, Connection: Female Threaded, Finish: Triple-Coat (Zinc Electroplate, Chromate And Epoxy Powder Coat), Standard: UL 886 (1203), UL File Number E10444, UL Listed for Class I, Groups B, C, d, Class II, Groups E, F, G, and Class II, CSA C22.2 No. 25, C22.2 No. 30, CSA 065181 Certified, For Connecting Conduit To Conduit