0.24″ to 0.47″ Liquid tight nylon strain relief. 1/2″ NPT thread size. Commonly used for wiring standard solar panel junction boxes. This is for 1/2″ conduit size holes, which is actually 7/8″. The 1/2″ refers to the inside diameter of standard conduit. Nearly all junction boxes and electrical boxes come pre-punched, but if you need to make your own holes use the Greenlee punch #7211BB-1/2 Simply push the cable through the liquid tight nylon strain relief and tighten dome nut for a quick installation. No disassembly is required. The nylon body material is resistant to most common chemicals and solvents. Meets UL requirements.