Mountain Bike Chain Tensioner, Anti Drop Bike Chain Retention for Bike Repair [Fixed Chain]: Minimize chain chatter and prevent chain loss caused by swinging the trailing arm under hard bumps, ensuring a secure riding experience. [Easy Installation]: Compact and portable, it can be effortlessly installed without the need to remove the chain, with no negative impact on the shifting system. [High Adaptability]: Suitable for bikes with traditional chains and frames with tubes, but not compatible with elevated designs. [Anti Break]: The elastic material in the middle of this chain fixer offers stability and prevents breakage, making it in various scenarios. [Quality Material]: Made of premium nylon material, this chain retainer providing a long service life. Spec: Item Type: Chain Retainer Material: Nylon Gross Weight: 29g / 1.0oz Color: Black Package List: 1 x Retainer 3 x Strap 1 x Accessory​