Specially optimized for use with the latest E-MTBs, the Guide RE brakes have the extra power you need to control the extra speed and additional weight that these bikes have. Ready for the most aggressive riding these mountain bike disc brakes adopt the same 4-piston hydraulic disc caliper from SRAM’s downhill brakes and DOT 5.1 brake fluid. This brake fluid is more heat-resistant, preventing brake-fade as you take on long descending sections.