Features and Benefits Fits most Overhead Valve applications Smaller size fits new Chrysler New World Engine and some Toyota four cylinders Comes in a handy plastic case Can work on the car or bench Magnet in tool body captures keepers for quick removal and valve disassemblyQuickly removes and installs valve keepers on most overhead valve engines. Works on valve stems from 4.5 to 7.5 mm and 5/16" to 3/8". Magnet in tool body captures keepers for quick removal and valve disassembly.