Mag 1, QT, 80W90 Gear Oil, Exceptional Protection Against Spalling & Other Wear, Especially Under Extreme Heat, Pressure & Torque Operation, Ensures Long Equipment Life, API Gl-5 & MT-1, Mack Go-J, SAE J2360, Limited Slip, Maintains Viscosity, Even Under Extreme Operating Temperatures, Resulting In Longer Fluid Life & Reduced Operating Costs, Extra Resistance To Thermal Degradation Provides Superior Protection Against Oxidation & Deposit Formation & Significantly Prolongs Seal Life.