#415/ #50 heavy duty chain
for 48cc, 49cc, 50cc, 55cc, 66cc, 70cc, 80cc, 2-stroke motorized bike engine
and 4-stroke engine. **Although Master Links are convenient we recommend getting a chain tool, extra chain and not using a Master Link at all. It's been our experience that master links often get caught on the chain guide pully, brake and are hard to find... Strait chain is far more dependable.