[Material]:The bike chain tightener is made of high strength aluminum alloy,which is lightweight,wear resistant,and sturdy for long time use [Feature]:Smooth and ,the with bright color,making your bike more cool and fashion [Function]:Easily adjust the tension of the bicycle chain to prevent it from falling,Provide a simple,effective,and adjustable way to tension a single speed system [Easy to Install]:The single speed chain adjuster tensioner is easy to use and install,light in weight,and is a good accessory for bicycle lovers [Application]:Fits 3/8 Inch (10 mm) axles,universally for ,single speed BMX,mountain bikes,road bicycles cycling,etc, Weight: 0.08 Pounds, Manufacturer: QUXVUIS