New TRP post-mount to post-mount rotor adapters for rotor sizes ranging from 160 mm to 223 mm. TRP's new adapters use a simple and easy approach to help you get the correct fit. “P” stands for “Plus”, immediately followed by the millimeters needed to elevate the caliper to your chosen rotor. If you have a post mount 180mm fork, like a FOX 36, and you would like to run a 203 mm rotor, you will need to lift the caliper 23mm, which will be the +23mm adapter.