pectro Heavy Duty Platinum Full Synthetic Sportster Transmission Lube (in short; STL) is a fully formulated SAE 75W-140 synthetic transmission lubricant engineered to work in all applications where the same oil lubricates the clutch, primary and transmission. A.P.I. GL-1 rated. Dyed green. Exceeds all known OEM and Harley-Davidson warranty requirements. The perfect lubricant for Sportsters and air cooled Buells.