All Wheels Manufacturing replacement derailleur hangers are produced in their Colorado shop to exacting tolerances. - CNC machined 6061 aluminum - Black anodized finish Notes: - Post on this hanger is 16.5mm (.650) in length with an M12 x 1.25 thread. Please check your hanger before ordering to make sure this is a match. - Trek recommends that you apply a removable thread-locker such as LOCTITE 243 to the threads during re-assembly. Failure to do so may result in fasteners loosening during use.