Hayes dominion a4 disc brakegiving enhanced control and stopping power to the rowdy riders of enduro, trail, downhill and e mtb rides, this excellent disc brake from hayes features an all new system. With its four piston technology, this intuitive brake setup features an adjustment for the lever travel and the pistons of the caliper for a defined increase in braking force when the pad contacts the disc. Easy to adjust hydraulic brakeswith a 2 stroke dual port bleed system for safe and efficient venting and a ball bearing brake lever with tool free dead stroke adjustment, maintaining the brake for top performance is simple and quick to let you get on with keeping your steed in control as master what the mountain throws at you. Featuresmaterial aluminiumbrake caliper post mountrecommended disc d seriesbrake pads t100, sinter metallic t106, sinter metallicbrake fluid dot 5.1 weight 310g approx buy hayes components from chain reaction cycles, the world's largest online bike store.