Race tested and proven to effectively lower brake temperatures, Ultra Cool Brake Fans save race teams money by extending rotor and pad life. Patent-pending brake fans are the only product currently available that cools the wheel side of the caliper, providing more CFM of cooling air, while remaining lighter and more cost-effective than traditional brake duct hose and blower systems. Product simply sandwiches between the hub and wheel, and may be double stacked for even greater air flow. Brake fans are sold as right or left applications, and are designed for use with 5/8" studs.