Features1Floating pulley and spring adjustment can achieve chain tension. 2Adopts bearing shaft and can be matched with a variety of guide wheels. The guide wheels generally use 11 teeth or 13 teeth. 3Can effectively prevent the chain from falling and reduce the gear feel. Suitable for people who like cycling. 4This bicycle chain tensioner is made of high quality aluminum alloy, durable, light and easy to install. 5Full CNC precision machining, anode color treatment, exquisite workmanship, beautiful and fashionable.SpecificationConditon: Item Type: Bicycle Chain TensionerMaterial: AluminiumAlloyColor: As Pictures ShownBrand: ZTTOFitment:Fit for most single speed folding bicycleFit forDahon most single speed bicycle(412 oval chain wheel)Fit forFnhon most single speed bicycle(412 oval chain wheel)Package List1 xRearChain Guide