Quickly Removes and Installs Valve Keepers On Most Overhead Valve Engines With Valve Stems From 4.5 to 7.5mm and 5/16" to 3/8". Makes valve component disassembly and reassembly fast and easy. Push or tap tool with a hammer to remove valve keepers. Magnet in tool body captures keepers for quick removal and valve disassembly. To install keepers, load in retainer on valve stem, then push or tap handle to install. Can be used on the car or bench. New smaller size works on Toyota four cylinder and Chrysler New World Engine applications.