The SRAM MRX Comp 6-Speed Gripshift Shifter Pair is a highly reliable twist-shift system designed as a direct replacement or upgrade for kids' bikes, entry-level mountain bikes, and casual hybrid commuters. Unlike SRAM's high-end mountain bike drivetrains that use proprietary pull ratios, the MRX line is explicitly engineered with a Shimano 2:1 actuation ratio. This allows the shifters to work seamlessly with standard Shimano rear derailleurs and cassettes.