Quicksilver 22-8M0058389 Magnetic Oil Plug Drain Kit BottomLower unit gear lube drain and fill hole screw and seal 8M0058389 is used with 3/8-16 drain/fill hole screw on all MerCruiser sterndrives, Mercury and Mariner outboards except the Verado series. It is very important to use the seal to make sure the drain/fill hole screw seats properly to retain the gear lube in the gear case and keep damage causing water out of the gear case.All MC-1, Alpha 1, Gen II, TR & TRSApplication: Fits Mercury MerCruiser I, R, MR, Alpha One, TR, TRS, and all outboards with Magnetic gear lube fill or vent 3/8-16 UNC threaded screws. Used with 3/8-16 drain and fill hole screw on all MerCruiser sterndrives, Mercury and Mariner outboards except the Verado series; Must use this seal to properly seat the drain/fill hole screw in the lower unit; Helps prevent gear lube from leaking out and water from seeping in to the gear case causing serious damage; This is the magnetic plug screw version - the magnet imbedded in the screw plug attracts any ferrous metal shavings to keep them from suspension in the gear lube and causing damage to gears; Produced to meet Mercury Marine original equipment manufacturer specifications to maximize the performance of your Mercury and Mariner outboard or MerCruiser sterndrive; Replaces: Mercury 22-67892A06; GLM 21731; Mallory 9-72651; Redline RL2375; Pro Marine 64892; Sierra 18-2375;