Tylaska H8 Halyard ShackleTylaska'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 Specifications A 3. 16" (80. 2 mm) B 1. 32" (33. 5 mm) C . 28" (7. 1 mm) D 1.