These are aluminum alloy adaptors to attach your Post Mount disc brake caliper to an IS mount. For adaptors that include orbital washers, please note that your brake caliper must be installed between the brassy-colored convex washers, reinstalled in the order they come in the kit.

*Also note that 180mm Front and Rear Adaptors, as well as 160mm Rear Adaptors the kit includes two pairs of IS mount bolts. The shorter 18mm pair is for standard, flat IS mounts like on our Polyvalent, Piolet, and Neutrino. The longer, 20mm pair is for older standard, wider-thickness IS mounts, found on many older disc-brake mountain bikes.