Works on 2004 and newer ford 4.6 and 5.4 l, 3 valve triton v-8 engines easy to turn feature makes starting thread fast use with compression testers with 14mm thread patent pending use with otc compression testers (or other compression testers with a 14mm thread) to access hard to reach spark plug holes.works on 2004 and newer ford 4.6 and 5.4l, 3 valve triton tm v-8 engineseasy-to-turn feature makes starting thread fasttriton is a registered trade mark of the ford motor co. – patent pending.