Smooth, rounded integral bushing in each hub to protect conductor insulation|Accurately tapped, tapered NPT threads for tight, rigid joints and ground continuity|One piece design eliminates need for disassembly during installation|Telescoping cylinder within cylinder design permits expansion or contraction|Small external diameters excellent in restricted areas in wiring of pumps, motors and other equipment|Internal phosphor bronze bonding jumper ring assures positive ground between telescoping cylinders|Expansion unions compensate for expansion and contraction of conduit|Female threaded connection