The ultimate in lightweight mountain bike chain catchers Designed to work with all double chainsets (adjustable for size) with external bottom bracket bearings It acts as a ramp to guide your chain & virtually eliminates the possibility of your chain dropping off the small chainring onto the bottom bracket helping to protect your frame & keep you in gear Please note this is not a DH chain device & is designed to help eliminate chain drop while shifting rather than guiding your chain around the chainring Mounts in place of a 2.5 mm spacer Adds only 17 grams of weight Made from 6061-T6 heat treated aluminium Long-lasting protective anodised finish K-Edge products are proudly CNC-machined in the USA & have a Lifetime warranty: you break it well replace it