The Ace AF1 Low features Hollow Kingpins for a lightweight, lower profile AF1. Carefully manufactured using our proprietary casting process, the AF1 has a 70% increase in the aluminum’s structural integrity, making it the strongest and longest lasting cast truck on the market. Truck height: 1.93" (49mm). Manufactured with high-quality AA 356.2 alloy using our own proprietary casting method. True T6 heat-treated baseplates and hangers. 4140 steel alloy axles, oversized to eliminate bearing wobble. Patent pending rethreading axle nuts - no more damaged axle ends! Durable Hand-poured 96a urethane pivot bushings for better response. Refined suspension for a cleaner turn. Top Bushing: 10mm tall, 91a hardness. Bottom Bushing: Bottom 12mm tall, 86a hardness. Machine-faced hanger ends for precise bearing contact.