These are heavy duty stainless steel ankle shackles. They lock in place with integrated screw locks. They are made of solid high quality heavy stainless steel polished to a mirror finish. They have the feel and security of the real prison shackles in a clean esthetic pleasing quality and without the grunge. The shackles come with a 1 foot (30.5cm detachable polished connecting chain allowing the shackles to be used independently or together with the chain. The Shackle inside diameter is 3-1/4 inches (8cm). Unisex style and use.