High braking power with precise dosing: Shimano Disc Brake BR-MT200 Hydraulic disc brake with a high, precisely metered braking force in the powerful design. Opposing pistons prevent vibrations. Natural mineral oil as hydraulic fluid, environmentally friendly and is neither toxic nor corrosive, in bicycle hydraulic braking systems, the optimal This simple to install conversion kit upgrades your stopping power by up to 20%. The existing 160mm disc will convert into a 180mm full circle type brake disc with this kit. As mountain bike discs use a 6 bolt standard centre hub internationally, you have a choice of either upgrading to a contour disc or full circle. An international bolt