The Shimano Altus SL-M315 Shifter offers light shifting operation, wide compatibility options, and is suitable for internal cable routing. Slim main lever body Numbered gear display is positioned below the handlebar and indicates gear position at a glance Shimano's Optislick cables feature a minimal and uniform electrically coated layer that improves cable routing efficiency and provides excellent corrosion resistance Rapid Plus technology is suited to quick shifting, giving riders the ability to downshift three gears in one stroke 2-way release means shifts can be released by pull of the index finger or push of the thumb 22.2mm handlebar clamp