The park tool dt 52 disc brake mount facing set is engineered and built to accurately face front or rear disc brake mounts so they are precisely aligned to the rotor park tool dt 52 disc brake mount facing set features the park tool dt 52 is engineered and built to accurately face front or rear disc brake mounts so they are precisely aligned to the rotor use of the dt 52 helps ensure proper disc brake setup and performance faces any is mount post mount or new s