This Harken 108 Rope/Wire Upright Lead Block is often used to lead spinnaker pole lift, cunningham, outhaul and other control lines from the mast base.Designed for vangs, outhauls or shrouds where wire is used or for rope where loads are too high for regular bullet blocks. Roller bearings handle high loads better than ball bearings. Sheaves are PTFE-impregnated, Hardkote anodized aluminum for strength. They deliver dependable fast trim and release under high or low loads.A range of styles lets these blocks adapt to almost all control line applications. Ideal for cunninghams, vangs, outhauls, traveler controls, spinnaker controls, barberhaulers, etc.Key FeaturesFixed, stand-up wire or rope lead block for a 90 degree turnUsed on many types of control systemsCorrosion-resistant stainless steel straps reinforce these blocksBall bearings, sheave and sideplates are UV stabilizedSheave Diameter: 1 1/8" (29 mm)Max. Line Diameter: 5/16" (8 mm)Max. Working Load (MWL): 500 lb. (227 kg)Breaking Load: 2000 lb. (907 kg)Weight: 1.5 oz. (43 g)Length: 1 1/2" (38 mm)Fasteners: Four #10 RH (5 mm)