Mounted in place of a front derailleur, the Chain Keeper works with single and 1x multi speed drivetrains using a narrow chain. The chain block surrounds the chain as it meets the chainring and prevents it from skipping off. - Accommodates a range of chain line measurements and chainring sizes - Not designed for downhill/freeride/big hit use - Color: Black - Chainguide Mount Type: Seat Tube - Front Derailleur Clamp: 31.8