Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to our popular Harken Big Boat blocks, these small, compact blocks have very high working loads for safe, easy trimming. Sheave Ø (mm)29 mm Length (mm)53 mm Weight (g)17 g Maximum line Ø (mm)8 mm Maximum working load (kg)150 kg Breaking load (kg)454 kg