HARKEN 100mm Aluminum Double Block — Swivel, 3248 Sailing Shackles & Swivels_Loups Winch drums are made of

Winch drums are made of black Hardkote anodized aluminum

UV-stable acetal sheaves provide durability for a long service life

Run multiple halyards and control lines aft from the mast to stoppers or winches for quick easy adjustment

Use a standard low-beam track when the track can be supported at each fastener hole

Simple design and construction for handling high static loads on cruising boats

HARKEN 100mm Aluminum Double Block — Swivel, 3248 Sailing Shackles & Swivels_Loups Winch drums are made ofBlack 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. Offered in 57 150 mm sizes, with low load versions in 57 and 75 mm ranges. A center cage keeps Torlon roller bearings separated and parallel to reduce friction. The sheave center carries the primary load,