This tool allows you to easily cut open your oil filter to inspect the paper filter element for contaminates and to detect problems inside your engine before they become major and expensive issues. This oil filter cutter will work with both styles of aircraft oil filters — those that have female threads and those that have male threads. This tool will cut filters from 3″ diameter up to 4-3/4″ diameter. Some of the newer aircraft filters have a thicker steel base plate. This newly designed filter cutter has the cutting wheel height and guide bearings located higher so the cutting wheel cuts above the thicker base plates (there is no need to remove the rubber filter gasket as other filter cutters instruct you to do).