Red Line Oil 75W90 NS GL-5 Gear Oil is a high-performance lubricant designed specifically for use in manual transmissions, differentials, and transfer cases. This 1 quart bottle of gear oil is formulated with advanced synthetic base oils and additives to provide superior protection against wear, corrosion, and thermal breakdown. It has a viscosity of 75W90 and meets the specifications of API GL-5 and MT-1, as well as many OEM requirements. This gear oil is suitable for use in both high-performance and daily-driven vehicles, providing excellent shifting and smooth operation.