Harken 29mm Block - Part No. 348F, with Sheave Ø (mm) of 29 mm and Sheave Ø (in) of 1 1/8 in, can handle a Maximum line Ø (mm) of 8 mm and Maximum line Ø (in) of 5/16 in. Its Maximum working load (kg) is 150 kg and Maximum working load (lb) is 330 lb. These low-friction Carbo Air blocks are both lightweight and strong, making them a reliable and affordable choice. They are designed to complement the popular Harken Big Boat blocks and offer high working loads for easy and safe trimming.