Hayes dominion a2 disc brakeready for fast and fun mtb adventures, this disc brake offers smooth and consistent braking performance on the most unpredictable off road rides. It features a standard sized brake lever with tool free reach adjust, which means that you can fine tune it to perfectly match your hand size, riding preferences as well as the terrain conditions. Hayes has also equipped this standard sized model with a two piston caliper that provides fast and reliable braking as you blast across the rock garden, tree roots and debris at speed. Expanding on the award winning dominion a4. The, dominion a2, targets cross country and trail riders. Dominion a2 features a two piston caliper. Dominion a2 includes all the performance from the dominion a4, utilizing a compact, two piston caliper. Dominion a2 features the proprietary quickbite² system for fast and consistent burnish, coupled with our d series rotor sold separately to manage the heat with less braking noise. Features use cross country, mtb piston 2 piston type disc brake fluid dot 5.1lever size standard hayes hayes k2 hose rotors sold separately caliper mount 74mm post mount pad type t106 semi metallic included, t100 sintered metallic included reach adjusttool free reach adjust pad contact adjust tooled lever pivot sealed cartridge bearingscaliper alignment crosshairweight 303gbuy hayes components from chain reaction cycles, the world's largest online bike store.