506-44 "Clear Step" Outside lead furling block. Unique design leads your furling control line outside of your stanchions for a clean lead aft to the cockpit. Stainless cheeks with Delrin(tm) ball bearing sheave ensure low-friction and high strength. Locks in place with a small set screw accessed through a small hole in the sheave. Maximum line diameter 1/2". For 1" Stanchions. Overall Width 3-1/8" (79mm), Thickness 1-1/8" (29mm), Safe Working load 750 lbs (350kg), Weight 5oz (142g)