Takes some of the load off the crew when furling the jib: the ratchet sheave holds in one direction, acting as a friction brake against the pull of the sail. It fits a standard 25mm (1in) guard rail stanchion, and the stainless clamping ring lets you mount the block at any angle. A stainless lever locks the swivel head if needed.
The body is a UV-stabilised composite of high-density nylon and glass-fibre reinforced polymer, with 316 stainless internal parts and a 12-faced anodised aluminium sheave.
