The Shimano Deore SL-M5100IL 2-Speed Left shifter features Rapidfire Plus Mono technology which is an intuitive and simple front control that empowers riders to shift both up and down with a single lightweight and compact lever. The SL-M5100 Left shifter provides light and responsive front shifting performance which improves efficiency and control. It offers a lightweight and compact design for a cleaner cockpit with an I-Spec EV mount.