Manufactured from billet 6061T6 aluminum, the Spidertrax Aluminum Hat packs incredible strength at an impressive weight of under 2 lbs (0.91kg). Designed specifically for rock racers, youll no longer have to retro fit other manufacturers hats to work with your bolt pattern. All hats are anodized in dark blue, using an anodizing process for double corrosion resistance. Please note this brake hat is designed exclusively for Spidertrax Rotors and Ultimate Unit Bearings with 5 or 6 lug 5½” (139.7mm) bolt circle (BC) patterns. If you need a brake hat for a 1 Ton (907kg) Unit Bearing (older style), please call and well be happy to assist.