From the folks who invented ball bearing blocks, this line of blocks boasts an excellent strength-to-weight ratio. The plastic in their sideplates, sheaves and balls makes them 30% lighter, 60% stronger and generally less expensive than equivalent conventional blocks.
The tiny 29mm block is extremely strong. 29mm doubles and triples feature a U-lock to hold the swivel in the front or side position, or allow it to spin freely. Use the 29mm Carbos as mainsheet blocks on dinghies, or for low-friction applications on any size boat.
Use the 40mm blocks for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats. The 40mm blocks handle loads similar to Harken's 2.25" blocks.
The 57mm blocks have an enormous working range that makes them ideal for main and jib sheets, spinnaker halyards and control lines. This range handles loads similar to Harken's 3" standard blocks.
The 75mm Carbo Blocks are the only all-plastic blocks with a safe working load over 1,200lb. Because of their large-diameter sheaves and fitted ball races, they release easily under load and keep weight to a minimum. Perfect for mainsheet systems on racing boats and cruisers looking for better performance at a reasonable price. The 75mm single block weighs in at a remarkable 6.9oz. including the shackle, and the double and triple blocks aren't much more, giving an extremely high strength-to-weight ratio.