Smartcage design with 113t pulleys allows for short cage and a 28t max low cog Largest Cog: 28 Chain Wrap Capacity: 37 Cage Length: Short Drivetrain Speeds: 7 Tourney RD-A070 Rear Derailleurs Smartcage design with 11/13t pulleys allows for short cage and a 28t max low cog. Item Specifications: Color: Black, Largest Cog: 28, Chain Wrap Capacity: 37, Cage Length: Short, Drivetrain Speeds: 7, Rear Der/Shifter Compatibility: Mountain, Rear Derailleur Mount Type: 10x1 Standard,