SLR stands for SHIMANO Linear Response. The New Super SLR design makes use of a friction-reducing mechanism in the caliper, lever and cable that improve response and modulation. Comfortable lever design for better rider comfort and control Slim & compact bracket with smooth surface with enclosed mechanism Light action, defined click engagement Short lever stroke response Powerful and controllable braking system Polymer coated cables to reduce friction Polymer coated shift cable For Road / Racing Bike