Mercury Marine High Performance Gear Lube is a premium quality gear lubricant that provides smooth, quiet shifting and reduces gear noise. It's fortified with high-performance additives which provide excellent protection against wear, rust and corrosion. Mercury Marine High Performance Gear Lube is designed to be used in all types of marine gears, including synchro rings and bearings. This product meets or exceeds the requirements of API GL4 specifications for use in transmissions, differentials and drive shafts. May be used with any outboard which uses a 3/8"-16drain/fillscrew. Fits all MerCruiser sterndrives and Mercury/MarinerOutboardsexcept those models of Japanese origin.