The Bridgeport 372 6-Inch Zinc Electroplated Malleable Iron Insulated Bushing can terminate threaded rigid or IMC to a box using a simple locknut. It features a plastic metaliner that prevents damage to wire insulation. Temperature rated to 105 degrees Celsius, the bushing is 1-1/8 inches long, has diameters of 5-13/16 inches and 7-3/16 inches and is solidly built to meet construction and general industry OSHA-recognized, NRTL-listed electrical standards.