Part No. 2677 Low-friction Carbo Air blocks are lightweight, strong, reliableand affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave (mm)75 mm Sheave (in)2 15/16 in Length (mm)159 mm Length (in)6 1/4 in Weight (g)772 g Weight (oz)27.2 oz Shackle pin (mm)8 mm Shackle pin (in)5/16 in Maximum line (mm)14 mm Maximum line (in)9/16 in Maximum working load (kg)1650 kg Maximum working load (lb)3639 lb Breaking load (kg)4535 kg Breaking load (lb)10000 lb