Tylaska’s halyard shackles have the highest strength-to-weight ratio of any existing halyard shackle on the market. A captive 17-4PH stainless pin makes for trouble-free operation. The all-metal machined line thimble allows for use as a 2-1 purchase without the wear or melting that occurs with plastic molded thimbles. Lines can also be permanently spliced for a fixed halyard. Using a high strength composite sleave bearing, Tylaska has created true 2-1 halyard shackles capable of handling the full rated load of the shackle. The size was made to fit standard sail headboards without adding any unnecessary weight. Strength was optimized by computer and then verified by numerous "make and break" destructive tests.