SUREALL SR series explosion proof reduction bushing is conduit connector, reducer, enlarger in hazardous classified area to connect one threaded end of conduit to another rigid conduit, one threaded hub of explosion proof lighting, explosion proof enclosure, explosion proof panel and explosion proof fittings to another conduit, one threaded hub of explosion proof enclosure to another metal explosion proof cable gland or fittings, whereas, the thread of ends are different, like NPT3/4" to NPT 1/2".