This box is used to "convert" a pair of "standard" handcuffs (e.g. Peerless Handcuffs, Smith & Wesson 100 Handcuffs, or (of course) Hiatt 2010 Handcuffs) to a nastier form of the hinged handcuffs. The cuffs are placed IN the box (which opens on one side is formed to close around the chain and bottom of the lock case on the cuffs). Next the clamp (which is made of steel) is applied to the box. Finally a padlock is passed through the clamp (or the end of a belly-chain and then a padlock on that). The cuffs can still be locked and double-locked, but they are MUCH more rigid when in this configuration.