This is the Cylinder Head for the OS .21 VZ-M Marine Engine, OSMG1627. / / FEATURES: Blue aluminum construction / Four hole mount design / / INCLUDES: One Marine Head w/pre-installed water outlet nipple, OSMG6008 / / REQUIRES: Inlet Plug Cap OSMG5188 / Screw set OSMG8673 / Inner Head (Head Button) OSMG5037 / / SPECS: Height: 0.51" (13mm) / Diameter: 1.5" (39mm) / / / tjt 080305 / ir/jxs