57mm Quad Block Swivel, Center Becket
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. 
Features:
Sheave Ø (mm) 57 mm
Sheave Ø (in) 2 1/4 in
Maximum line Ø (mm) 10 mm
Maximum line Ø (in) 7/16 in
Maximum working load (kg) 1080 kg
Maximum working load (lb) 2380 lb