Harken^® Bullet Block In-Line Exit is designed to be compact and lightweight with a sheave diameter of 1-1/8" (29 mm). This low-friction turning block leads control lines out of the base of a mast or boom or passes line through decks of smaller sailboats. Delrin^® ball bearings ride on flat races for ultimate low-load performance, yet they are capable of working loads of up to 400 pounds (181 kg). The sheaves are crafted from Delrin and are UV-stabilized with a carbon black additive for maximum protection. It's cover plate and side plates are made from marine grade stainless steel for strength and resilience. Designed for all control applications on smaller boats where up to 5/16" line is used, this block has a fast trim and releases under both high and low loads. Easy maintenance: just flush with mild soap and fresh water. The Harken Bullet Block In-Line Exit is ideal for vangs, outhauls, cunninghams, flag halyards, traveler controls, barberhaulers, furling line leads and more.