SEI MARINE PRODUCTS- Mercury Mariner Force Gearcase Seal Kit 26-85090A1 13.5 15 18 20 25 HP This gearcase seal kit replaces OE#: 26-85090A1 and fits Mercury, Mariner, and Force outboard lower units with the following applications: 18-25 hp 2 stroke 1984-2005 and 13.5-15hp 4 stroke 1983 and older.