Features and Benefits: Unique and patented design works on 2004 newer Ford F-150 pickup trucks with 5.4L 3-valve Triton V-8 engines; Extension is part of the socket and easily fits down spark plug tube into the cylinder head; Soft rubber insert holds and protects spark plug during removal and installation; Socket has 3/8 inch drive for use with a ratchet or breaker bar; Socket end is 9/16 inch;