Same as the Schaefer 200 Series fairlead blocks, but with twice the working load. Use #10 fasteners. Configuration: Lead block Sheave: UV-stabilized white Delrin Ball Bearings: Delrin Sheave Size: 1-7/16" (37mm) Line Diameter: 7/16" Cheek Material/Finish: Polished stainless Safe Working Load: 1,000lb.