Transmission Rear Derailleur 18 Speed Road Mountain Bike Accessories and Features: Great transmission function. Alloy construction leads to lower weight without compromising strength and durability. It will be replacement part for the of your for 18-speed bikes. Specification: Product Name: Rear Derailleur Metal, Size: app.15cmx8cm/5.91''x3.15'' Color: Silver+Black+Red Quantity: 1 Pc Note: 1.Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Rear Derailleur (without retail package)