The Carbo Air blocks offer incredible strength and affordability, making them an essential companion to our renowned Harken Big Boat blocks. These compact, lightweight 40mm Cheek Blocks with a high maximum working load of 220 kg (485 lb) are perfect for safe and efficient trimming. Part number 2163 features a sheave diameter of 40 mm (1 9/16 in) and can accommodate lines with a maximum diameter of 10 mm (3/8 in).