The Alivio SL-M3100 Left Shifter provides responsive rear shifting for 9-speed mountain bike drivetrains.Features-Rapidfire Plus technology is suited to quick shifting, giving riders the ability to downshift three gears in one stroke-Optical gear display is positioned below the handlebar and indicates gear position at a glanceItem Specifications-Drivetrain Speeds:9-Front Der/Shifter Compatibility: Mountain-Shifter Style:Trigger-Double or Triple:Triple