Reducing Bushing – Haz Loc, Thread Gender Female to Male, Trade Size 3 1/2 in, 4 in, Compatible Conduit Type IMC, Threaded RMC, Compatible Conduit Trade Size 3 1/2 in, 4 in, Ends – Hazardous Fittings 3 1/2 in FNPT x 4 in MNPT, Overall Length 1 7/16 in, Weight 1.06 lb, Iron, Finish Chromate Coated, Powder Coated, Electroplated, Hazardous Location Rating Class I, Division 1 and 2, Groups B, C, D, Class I, Zone 1 and 2, Groups IIA, IIB + H2, Class II, Division 1 and 2, Groups E, F, G, Class III, RB