Automatic Chain tensioner slack adjuster w/ sprocket chain guide.

This engine attach Automatic Chain Tension feature is a great enhancement over the standard clamp to stay fixed idler.   

With this spring loaded tensioner with a 10T sprocket chain guide means you might never have to adjust chain tension again.   

Keeps constant tension on your drive chain to overcome loose or stretched chains that will occur over time. 

Attaches to the drive cover of any Chinese 2 stroke bicycle engine.