One of two tripod wrenches here, with a central cog operating the legs which gripped the filter body. You need a 3/8-inch square drive or 1/2-inch if the adaptor is used. The Clarke is handy when access is limited and the filter can only be tackled from under the engine with an extension on the ratchet. Yet while it worked well, as the pressure was released to turn the ratchet, it lost grip, so two hands were needed all the time.