BQLZR Silver Chain D Rigging Shackle For Boat 1/4 304 Stainless Steel Dee Type Pack Of 2 Made of 304 stainless steel for maximum corrosion resistance and durability. Side and racking loads may twist or bend a D-shackle.D-shackle is used to attach halyards to sails. The small loop can take high loads primarily in line. Side and racking loads may twist or bend a D-shackle.D-shackle is used to attach halyards to sails.