These shackles take the place of S-hooks. Unlike S-hooks they can be used multiple times. They are also much easier to install then S-hooks. They are stronger and some cities and parks are requiring their use instead of S-hooks. It is made of C45 forged steel.  This shackle is 5/16” with 3/8” x 1 ½” bolt.  This shackle is 5/16” with 3/8” x 1 ½” bolt.   There is a ½” opening at the bolt and at the widest, it is 1”. This will accept up to a ½” chain. Tensile strength is 12500 lbs.