HARKEN 100mm Aluminum Double Block — Swivel, 3248 Sailing Shackles & Swivels_Loups Light but durable TPU fabric

Light but durable TPU fabric with fully welded construction

Lifetime warranty against breakage

Winch drums are made of black Hardkote anodized aluminum

Offered in 57 - 150 mm sizes

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

HARKEN 100mm Aluminum Double Block — Swivel, 3248 Sailing Shackles & Swivels_Loups Light but durable TPU fabricBlack 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,