Lightweight, durable, and reasonably priced, the Low-friction Carbo Air blocks are a valuable addition to our renowned Harken Big Boat blocks. With impressive working loads, these compact 57mm Triple Fiddle Blocks feature a Swivel design and Reinforced Cam Arms for safe and effortless trimming. Part No. HSB378, they have a Sheave Ø of 57 mm (2 1/4 in), can accommodate a Maximum line Ø of 10 mm (7/16 in), and have a Maximum working load of 1080 kg (2380 lb).