1/2"-14 NPT Industrial Magnetic Drain Plug (External Head) IP-04X 1/2" NPT External Square Head Magnetic Drain Plug. 9/16th Head Easy to install. Replaces your existing oil drain plug. Removes ferrous metals from the oil that led to damage. Extends the life of your engine or gears. The Gold Standard in Engine Protection! Accept NO substitutions. Installed in the factory on some high-end products. We bring that superior engine protection to you!