Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave Ø (mm)57 mm Sheave Ø (in)2 1/4 in Maximum line Ø (mm)10 mm Maximum line Ø (in)3/8 in Maximum working load (kg)359 kg Maximum working load (lb)792 lb