This kit replaces the stock oil pan drain plug giving you an easy access drain for your oil. Run it through your bilge drain or connect an oil pump to the end. The drain end cap is 3/4" O.D. and fits through a standard drain hole. Models with 1/2-20 threads fit most Chevy, Ford and Olds pans while the metric model fits some late model Mercruiser engines. Oil Drain Kit 42" 1/2-20 threads