The 40mm Harken Block with Swivel (Part No. 2636F) is designed for use in fishing and offers a sheave diameter of 40mm (1 9/16 inch), making it suitable for lines up to 10mm (3/8 inch) in diameter. With a maximum working load of 220kg (485 lb), this block is both lightweight and strong, providing reliable and affordable performance. As a companion to the Harken Big Boat blocks, it is ideal for safe and easy trimming.