M-series rear derailleurs are designed to work with 7, 8 ,9-speed -compatible mountain and road shifters. Marvo LT rear derailleurs are made in precision rigid aluminum construction. Let these miracle workers get any bike rolling again. Light weight aluminum construction. Steel pulley cage for extra chain-rub durability. Compatible with 7, 8, 9-speed mountain and road systems. Item Specifications: Rear Derailleur Mount Type:: 10x1 Standard, Drivetrain Speeds:: 7,8,9, Cage Length:: Long, Chain Wrap Capacity (teeth):: 45teeth, Largest Cog:: 34, Color:: Black, Weight:: 317g, Rear Der/Shifter Compatibility:: Mountain,