R-series rear derailleurs are designed to work with 7, 8 ,9, and 10-speed -compatible road shifters. These R10 aluminum rear derailleurs are lightweight, precision CNC-machined, robust, and can get any bike back on the road. Short cage for double 28t setup. Light weight all aluminum construction. Steel cage. Compatible with 7, 8, 9, and 10-speed road systems. Not compatible with Tiagra 4700 road system. Item Specifications: Cage Length: Short, Chain Wrap Capacity (teeth): 33, Color: Black, Drivetrain Speeds: 10, Largest Cog: 28, Rear Der/Shifter Compatibility: Road, Rear Derailleur Mount Type: 10x1 Standard, Weight: 218,