Aqua Lube Lower Unit Oil is a specially formulated gear oil designed for use in lower unit gear assemblies of high performance outboard and inboard stern drive engines. Aqua Lube Lower Unit Oil is formulated from high viscosity index gear oil base stocks and formulated with a highly effective anti-wear , anti-scuff, extreme pressure additive package. A special synthetic tackiness additive clings tenaciously to gears to assure full lubrication under the heavy loads typical of marine engine acceleration. 80W90T viscosity provides complete lubrication even in coldest weather. Aqua Lube 80w90T has been tested and certified to exceed API GL-4, GL-5 and GL-6 standards.