Bike Single Speed Chain Tensioner Roller High Quality - Made of aluminum alloy and POM, with improved CNC process, our bike single speed chain tensioner is lightweight, rust-proof and durable.Universal Fit & Adjustable - Universal for single speed mountain bikes road bikes cycling. Our bike chain tensioner is more compatible, easy to install and convenient to use.Single Speed ​​Chain Tensioner - We know how frustrating it is that bike chains can always easily fall off, that's why we developed the premium aluminum chain tensioner to provide a simple, effective and adjustable way to tighten a single speed system and prevent the chain from falling off. Compatible with 7-12 speed chains The newly improved roller design is compatible with 7-12 speed chains, with the chain placed on the roller for smooth operation. In addition, 2 fixing screws and a thickened main body have been added to improve stability and effectively prevent loosening. Easy to Install Includes simple installation tools. The chain tightener is easy to install. (We recommend viewing our pictures and installation videos for installation) Please noted Adjust the bike chain roller center and the cassette center to the same horizontal level as possible. Package Includes Come with 1 piece bicycle tensioner at 1 speed, 2 piece different wrench for installation.