FeaturesTapered internal threads for watertight/dusttight unionThreads relieved to prevent bottoming of conduit, ensuring sound assemblyRecessed sealing ring at box end, sealing ring captivatedHardened steel/malleable iron/copper-free aluminum locknuts designed to provide high quality ground continuity, extended reach of locknut permits clamping on thin boxes and enclosuresInsulated throat, insulates conductors, prevents abrasion and thinning of conductor insulation, reduces wire pull effortWhen used with neoprene o-ring, provides watertight threaded hub on enclosures105 deg C temperature5/16 in THK maximum wallRain tight, watertight and dusttightNylon insulated