The Harken 29mm Block - Swivel Part No. 340 offers a sheave diameter of 29 mm (1 1/8 in) and a maximum line diameter of 8 mm (5/16 in). With a maximum working load of 150 kg (330 lb), this low-friction Carbo Air block is lightweight, strong, reliable, and affordable. It is a perfect companion to the popular Harken Big Boat blocks, providing high working loads and safe, easy trimming capabilities.