This specially formulated synthetic transmission fluid is designed for extended drain and severe service in heavy-duty manual transmissions that require a non-EP gear or transmission fluid. Castrol Syngear CD 50 is formulated from a synthetic base stock with a high-viscosity index and low pour point, and provides superior all-climate, year-round performance. It also contains an anti-wear additive, as well as rust, oxidation and corrosion inhibitors.