THESE PREMIUM GRADE CAST IRON HATS MAKE IT POSSIBLE TO USE BOLT-ON ROTORS ON VEHICLES EQUIPPED WITH INTERNAL SHOE PARKING BRAKE ASSEMBLIES. EACH HAT IS A PRECISION MACHINED, THREADED HOLE DESIGN FOR USE IN CONJUNCTION WITH THROUGH-HOLE MOUNT ROTORS. AFTER MACHINING, THE HATS ARE ELECTRO-COATED FOR CORROSION RESISTANCE.