Full Technical Description: Taper Threaded Type; Natural Aluminum Material; 2-1/2 Inch Small End Trade Size; 3-1/2 Inch Large End Trade Size; UL 886, CSA C22.2 Approval; Class I Div 1 and 2 Group B C D, Class II Div 1 and 2 Group E F G, Class I Zone 1 and 2 Group Iia Iib + H2, Class III Enclosure; Constructional Feature Explosionproof/Dust Ignitionproof; Used on Threaded Imc/Rigid Metal Conduit; Application Hazardous Location; Applicable Standard Nec/Cec; RB Model