AF1 Hollows feature hollow axles and kingpins. The all-new Ace AF1 features game-changing performance without deviating from the original Ace geometry. The AF1 is carefully manufactured using a proprietary casting process. Years in development, the ACE AF1 has a 70% increase in the aluminum's structural integrity, making it the strongest cast truck on the market. Includes 2 Trucks. Size 66 features a 9.0" axle width.