Sram guide ultimate disc brakewith its completely new 4 piston s4 caliper swinglink lever cam and carbon lever blade the 360 gram guide ultimate stands alone as the new leader in its class it has been engineered to be light and powerful with superior heat management capabilities which give you better more consistent more reliable braking the new caliper design also incorporates a re designed seal and aluminium piston interface for ease of setup and improved consistency while bleeding e