Adaptors available for Shimano, SRAM, Hope, Hayes, Formula etc. rotors:CNC machined from 6061 T6511 aluminum. Machined surfaces allow for better caliper alignment and a more rigid brake setup.The Post Mount standard is universal for front and rear brakes.Frames and forks that use the post-mount brake interface use a stock size that varies from 160mm–203mm. It's important to check your frame and fork for the default post mount size before ordering a suitable adapter.To calculate the size of the required adapter, subtract the frame/fork stock mount size from the desired rotor size.Specifications:- 203mm