Mercruiser Inboard. This size is usually only found on the cast aluminum oil pans used by Mercruiser and Crusader.
Easy Oil Drain Kit
It's quick and easy to drain engine oil without a pump. Simply push the Hose through the transom drain plug hole or place anywhere below oil pan. Assembly includes oil resistant Hose with non-corrosive brass fittings. Available in sizes to fit most I/O marine engines.
The hose is 42" long.