Crouse-Hinds series GUB explosionproof instrument enclosures are used to enclose ammeters, voltmeters, wattmeters, varmeters, power factor meters, tachometer indicators, pressure controls, etc., in a threaded rigid metallic conduit system. GUBs are approved for use in Class I and Class II hazardous areas often encountered in oil refineries, chemical plants, paint and varnish manufacturing plants, coal processing locations, grain processing plants, and other industrial applications.