Big Brake Dynamic Flared Bell hats are precision machined from premium aluminum alloys for high strength and attention to minimized weight. Hats in this category feature dynamic mount t-nut mount holes for use with standard through-hole mount rotors. When used in conjunction with matched Wilwood rotor hardware kits, Big Brake Dynamic hats provide solid, reliable performance in the most demanding conditions. Short Offset Hats are for narrow space applications and maximize clearance. They are available for most rotor bolt patterns in a variety of four and five lug wheel patterns.