The billet SL4 caliper incorporates Wilwood's latest technology in a conventional 3.50" centered lug mount design, with weights starting at 4.94 pounds. This caliper series has been structurally designed for high clamping efficiency and low deflection in a body width compatible with all wide 5 and 5 x 5 style hubs. It is a direct replacement for all other Superlite style calipers.