Companions to the popular Harken Black Magic block line, these small, compact blocks work well with very high working loads for easy trimming Low-friction Carbo AirBlocks are lightweight, strong, reliable—and economical. Consistently 30% lighter and 60% stronger than equivalent Classic blocks. Harken 75mm Carbo Air Quad Block allows either a high-load purchase of 5:1 to 6:1, and the sideplates are UV-stabilized, high-strength resin and designed for small-diameter lines favored by racers. Good for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats This innovative line of blocks turns fiber-reinforced composite construction into a reliable strength-to-weight ratio you can depend on. The Harken 75mm Carbo Air Single Block allows either a 2:1 or 3:1 purchase. Low-friction Carbo AirBlocks are lightweight, strong, reliable—and economical. Consistently 30% lighter and 60% stronger than equivalent Classic blocks. The sideplates are UV-stabilized, high-strength resin and designed for small-diameter lines favored by racers. Good for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats. Recipient of both the Dame Award and Sail Magazine’s Freeman-Pittman Award for innovation, this innovative line of blocks turns fiber-reinforced composite construction into a reliable strength-to-weight ratio you can depend on. Companions to the popular Harken Black Magic block line, these small, compact blocks work well with very high working loads for easy trimming. Key Features High strength-to-weight ratio block Harken’s most innovative blocks 30% lighter, 60% stronger than equivalent conventional blocks Smaller block for jib and mainsheet systems on high-performance dinghies Use for high-load control lines on small keelboats Stainless steel swivel shackle Sheave Diameter: 2 15/16" (75 mm) Max. Line Diameter: 9/16" (14 mm) Max. Working Load (MWL): 1213 lb. (550 kg) Breaking Load: 3638 lb. (1650 kg) Weight: 6.9 oz. (195 g) Length: 5 3/8" (137 mm)