All Wheels Manufacturing replacement derailleur hangers are produced in their Colorado shop to exacting tolerances. - CNC machined 6061 aluminum - Black anodized finish - Includes (2) M4x8 Flat Head Screws Note: The mounting holes on Wheels Mfg DROPOUT-138 are 23mm apart, center-to-center. Do not confuse this hanger with Wheels Mfg DROPOUT-120.