The shimano xtr m9020 trail hydraulic disc brake set is a pre bled trailall mountain disc brake it has been designed to seamlessly adapt to extreme terrain changes with the highest level of braking the high rigidity aluminium calliper means improved modulation and response and the insulated pad coating and pistons means a more advanced heat control for a stable performance in extreme conditions the lever uses a new servowave design and a sil tec coated roller which means decreased friction