This unique lubricant was developed for Harley owners who were unhappy about their noisy 6-speed transmission. It provides smoother shifting, reduces fifth gear whine and eliminates clunks. Spectro's proprietary formula uses G4 Technology, special additives that provide additional anti-wear protection, higher film strength between the gears, and reduces drag while extending gear life. High loads and extreme heat do not affect the oil, so it performs perfectly when pushed hard and long. A.P.I. GL-5 rated. Dyed red. Exceeds all known OEM and Harley Davidson warranty requirements.