The Wolf Tooth Roadlink derailleur hanger extension is a unique patented device that offsets the position of your road derailleur to make it possible to run a wide-range mountain bike style cassette. It is an ideal solution for riders looking to convert their road, gravel, cyclocross, or commuter drivetrain bike to attain the simplicity and reduced weight of a single front chainring but without giving up the gear range of a double. It's also great for riders with double chainring bikes that want lower gearing for those ultra steep climbs. It does not compromise the shifting in the smaller cogs of the cassette but yet it enables the derailleur to work with as large as a 40T cassette. Wolf Tooth Roadlink Features Easily installed in less than 5 minutes by any home mechanic. The RoadLink mounts only to standard derailleur hangers. Wolf Tooth Roadlink Compatibility 10s Cassette Compatibility: 11-32: Not Required (GS medium cage rear derailleur works) 11-34: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-36: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-40: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-42: Not supported 11s Cassette Compatibility: 11-32: Not Required (GS medium cage rear derailleur works) 11-34: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-36: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-40: Single (for double chainring be sure to not exceed the derailleur's capacity) 11-42: Not supported 10-42: Not supported Wolf Tooth Roadlink Specifications Weight:  17g Material:  6061 aluminum Included:  stainless steel bolt Torque:  8-10Nm Made in the USA