Specifications: This product is used for rear derailleur extension, apply for 40T/42T/46T/50T mountain freewheel or 32T/36T road flywheel. Expand the flywheel speed change more smoothly. Aluminum alloy material, CNC workmanship, solid and firm, very durable. Great accessory for cycling enthusiasts.Type: Bicycle Rear Derailleur Hanger Material: Aluminum Alloy Length: 45.5mm/1.79" (Approx.)Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.Package Includes: 1 x Bicycle Rear Derailleur Hanger 1 x 10mm Fixing Screw