1.Model: ARDTY21BGSDL Black Rear Derailleur,Suitable for 6/7speed 2.High-Performance: This rear derailleur is forged with high-hardness aluminum alloy and adopts a hollow weight-reduction design, which makes it lightweight and stable during speed changes 3.Precise Adjustment: The body of the rear derailleur is adjusted by high-hardness aluminum alloy, ensuring precise adjustment and accurate speed change performance 4.Fast Installation: The installation is fast and convenient, and easy to maintain Note: 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. Sold by-Minnanxin