Red Line's V-twin primary case oil is designed specifically for 1984-to-present V-Twin American motorcycle engines, including aftermarket engines of similar designs. Similar to Red Line MTL, this product is for use in the primary chain case with wet-diaphragm spring clutches. Designed to operate over a wide temperature range, V-twin primary case oil improves clutch operation, while reducing wear and temperature. Where most synthetics are too slippery for clutch operation, this friction-balanced product is designed to provide less slip, smoother operation, and more power in modified engines