Flush contaminates from your lower unit cooling system. Quickly removes salt and mineral build-up with a simple flush that slips over side water inlets on most inboard and inboard/outboard lower units. Fits Mercury/Mariner 20hp and higher outboards, 9.9/15hp. 4-stroke Big Foot outboards, 2005 & newer 8/9.9 hp 4-stroke outboards, 15hp 4-stroke outboards, all MerCruiser sterndrives (except Bravo One Perf. & Blackhawk) and MHP TorqueMaster gearcases. NOTE: 2000 and newer V-6 outboards and MerCruiser Bravo drives with dual water pick-up also require dual water pick-up flush seal kit, Quicksilver # 881150Q 1.