Wilwood's Sprint Fixed Mount Rotor Hats have a long standing reputation for fit, performance, and durability. This special version of HD Series hats are manufactured from premium grade aluminum alloys offering high strength, low weight, and quality appeal. HD hats feature a straight bell construction with a flanged rotor mount ring. These features combine to provide maximum radial clearance between the caliper body and the hat. This can be a critical factor when trying to squeeze a large caliper inside a small wheel. Offered in a 6 Lug configuration for popular Sprint Car Wheels and Hubs. Through hole hats for use with threaded-hole, 8 x 7.62 mount rotors. When used with matching Wilwood rotor hardware, these hats provide solid mounting for a wide range of custom and competition disc brake applications.