Black Magic Air blocks are a top favorite of Big Boat performance racers and cruisers. These lightweight, free-running, powerful performers are used for sail controls that see lots of action: mainsheet, runner, halyard, and spinnaker systems. A center cage keeps Torlon® roller bearings separated and parallel to reduce friction. Shackle blocks lock in two directions or swivel to keep line from twisting. Torlon is a registered trademark of Solvay Advanced Polymers L.L.C. SPECIFICATIONS RESOURCES SPARE PARTS Sheave Ø (mm)100 mm Sheave Ø (in)3 15/16 in Length (mm)203 mm Length (in)8 in Weight (g)623 g Weight (oz)21.98 oz Shackle pin Ø (mm)10 mm Shackle pin Ø (in)3/8 in Maximum line Ø (mm)16 mm Maximum line Ø (in)5/8 in Maximum working load (kg)3402 kg Maximum working load (lb)7500 lb Breaking load (kg)6804 kg Breaking load (lb)15000 lb