Al Union Thread Gender Male to Female Trade Size 3 1/2 in Ends - Hazardous Fittings 3 1/2 in FNPT x 3 1/2 in MNPT Overall Length 4 1/4 in Outside Diameter 5.06 in Overall Width 5 1/16 in Weight 1.79 lb Aluminum Finish Unfinished Hazardous Location Rating Class I Divisions 1 and 2 Groups A B C D Class II Divisions 1 and 2 Groups E F G Class III Divisions 1 and 2 UNF For Use With IMC Rigid Conduit Threaded Conduit Conduit Fitting Type Union