Wilwoods AT6 forged aluminum racing caliper is designed, engineered, and purpose built to endure the rigors of off - road truck and buggy racing. The AT6 combines the latest technologies in manufacturing materials and processes in the most popular mounting configuration built tough enough for Baja. The caliper covers a wide range of racing classes in SCORE, BITD, Ultra - 4, Pre - Runner, and all similar sanctions of desert and off - road competition, and is well suited for both short course and endurance length events. AT6 calipers feature high - strength, lightweight forged aluminum lug mount body with the popular 6.88 mount centers. MIL - Spec Type III hard anodizing is applied to all surfaces on all models for long wear and abrasion resistance. A massive bolt - in center bridge support adds stiffness and top - side pad access. Thermlock pistons are also available as an upgrade.