UNILETS® Explosion proof, dust-ignition proof recessed head close-up plug for use with threaded rigid metal conduit and IMC. Made of copper-free aluminium. Used to seal threaded NPT conduit entries in hazardous or non-hazardous location enclosures. Smooth, rounded integral bushing in each hub protects conductor insulation. Accurately tapped, tapered threads for tight, rigid joints and ground continuity.