Hayes caliper assembly kit dyno sport dyno is a compilation of 13 years of brake design starting with the original mag brake in 1997 it has an industry first piston and master cylinder bore design inspired by the powerful prime brake platform this is our most durable design to date featurs lifetime leak proof warranty vesrah yellow performance pads long wear semi metallic pads 25 fixed lever blade reach weight400g body and caliper colorblack w silver white w black optional hose