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) 40 mm Length (mm) 94 mm Length (in) 3 11/16 in Weight (g) 170 g Weight (oz) 6 oz Shackle pin Ø (mm) 5 mm Shackle pin Ø (in) 3/16 in Maximum line Ø (mm) 10 mm Maximum line Ø (in) 3/8 in Maximum working load (kg) 660 kg Maximum working load (lb) 1455 lb Breaking load (kg) 1383 kg Breaking load (lb) 3050 lb