Harken 57mm Black Magic® Double Block allows a 2:1 or 3:1 purchasing system.
The entire line of Black Magic® AirBlocks® offer a sleek and polished look. Their unique performance engineering remains the staple of the Black Magic line of blocks. These strong, lightweight blocks feature free-rolling, high-load Torlon® roller bearings for a high strength-to-weight ratio. Used for dynamic high load sail controls including mainsheets, runners, halyards and spinnaker systems.
Air blocks are easy to clean and service. They have few parts and no loose balls or rollers to misplace. Unlike blocks that are riveted, fasteners allow quick disassembly with a single hex wrench.
Lightweight blocks with high-load Torlon® roller bearings for a high strength-to-weight ratio
Ideal for sail controls including mainsheet, runner, halyard, and spinnaker systems
Center cage keeps Torlon® roller bearings separated and parallel to reduce friction
Sheaves have radiused edges to protect today’s high-tech line