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)66 mm Weight (g)26 g Shackle pin Ø (mm)4 mm Maximum line Ø (mm)8 mm Maximum working load (kg)150 kg Breaking load (kg)454 kg FootnoteMaximum working loads and breaking loads for blocks based on cam strengths.