Low-friction Carbo AirBlocks® are lightweight, strong, reliable—and affordable. Companions to the popular Harken® Black Magic® line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave Ø (mm)29 mm Length (mm)85 mm Weight (g)54 g Shackle pin Ø (mm)5 mm Maximum line Ø (mm)8 mm Maximum working load (kg)299 kg Breaking load (kg)737 kg