brand new and high quality Features: Made of high quality materials, durable and practical. Easy to install and use, provide good usage experience. Wonderful accessory for mountain bike. Specification: guide screw for 4/5/6MM axis Uses: For most of the rear derailleur, support 7/8/9/10 speed! Guide the selection principle: 1: Try to use the same way as the original guide wheel size, not the same, you can choose more than the original guide wheel small, cannot. choose large. 2: The guide wheel and the tension wheel does not distinguish, but is not the same dial the original guide wheel and the tension wheel size some, can be changed, but the chain need to re adjust the length. Bike Guide Wheel only,other accessories demo in the picture is not included! Specification: Material: Aluminum Alloy Optional Diameter: 11T, 13T 11T Diameter: app.4.2cm/1.65in 13T Diameter: app.4.9cm/1.93in Optional Color: Black, Blue, Golden, Red, Silver Quantity: 1 Pc Note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Contents: 1 x Bike Guide Wheel