Conduit Reducing Bushing; Type Flush; Large End Trade Size 4 Inch; Small End Trade Size 2-1/2 Inch; Length 1-1/2 Inch; Enclosure Class I Div 1 and 2 Group B C D, Class I Zone 1 and 2 Group IIA IIB+H2, Class II Div 1 and 2 Group E F G, Class III; Material Electro Zinc Plated Malleable Iron; Approval UL 886, CSA C22.2; Used On Rigid Conduit/IMC