These shackles take the place of S-hooks. Unlike S-hooks they can be used multiple times. They are also much easier to install than S-hooks. They are stronger and some cities and parks are requiring their use instead of S-hooks. This shackle is 2 1/8″ long. The ID is 3/4″ and the opening is ¬Ω”. This shackle works with our swing hangersandchains. This product should last 2 years in harsh conditions and up to 5 years in optimal conditions. Some conditions may require replacement sooner. Tensile strength is 8000 lbs.