S & G Tool Aid's 12mm and 16mm Compression Test Adapter for Ford Triton Engines, No. 34020, features a dual-threaded male end that provides two adapters in one for testing compression at the spark plug ports on Ford Triton Engines. The 16mm-1.50 male end is used on three-valve Triton engines for 2004-'08 5.4L Ford F-150 and 2005 4.6L Ford Mustang. The 12mm-1.25 male end is used on 2009 Triton 4.6L, 5.4L and 6.8L engines. On the end opposite the dual male threads is a 14mm-1.25 female thread that fits most compression testers.