Serious shifting performance for a recreational world. Whether your ride of choice includes gently rolling terrain or hardcore downhills, the MRX Pro and MRX Comp will follow you there with crisp, positive response on your shifts. Performance:: Recreation. Technology:: SRS technology for light precise indexing. Speeds:: 678. Indicator:: Quick View Ledge. Body:: 50mm Overmolded Shory wlightweight GrilonR molded finish, super soft dual density grip. Compatibility:: ShimanoR rear derailleurs, SRAM or ShimanoR front deraileurs. Other:: Easy cable change, Index Micro adjust front shifter options.