Materials This chain tensioner is made of iron and galvanized, providing a sturdy construction with a long service life. Main function Designed to engage the rear wheel to prevent forward movement and to maintain proper chain tension across all gears. Easy to Use The adjustment mechanism controls the rear wheel tension and keeps the wheel firmly in place during use. Widely Used Compatible with road bikes and stationary bikes that have a rear fork, and also suitable for mountain bikes. Usage scenarios - Road bike or commuter: Replace an aging or worn tensioner to ensure consistent chain tension across all gears and prevent slipping during shifts. - Mountain bike: Install on bikes with a rear fork to keep the chain taut and reduce derailment risk on rough terrain. - Stationary bike or trainer: Maintain stable chain tension during intense workouts, ensuring smooth and quiet operation.