These stanchion lead blocks have free-rolling ball bearings to lead line aft for safe furling from the cockpit. Use the 7401 40mm block on the bow pulpit as an inboard lead. The 7402 features a ratchet to control spooling when unfurling. The 7401 and 7402 have ball and socket bases to align blocks for smooth leads aft. The 7403 has a 29mm sheave and allows the furling line to travel outboard of the stanchion to keep the side deck clear. Mounts to stanchion with a four-screw clamp. Material: UV-stabilized glass-fiber, nylon resin side plates Maximum Line Length: 3/8" (10mm)