Despite being a common method of restraint, handcuffs have one very, very serious flaw; the locks are all the same. A standard handcuff key will fit into literally any standard pair of handcuffs.
Which allows, say, a lockpick company like Sparrows to, say, hide a handcuff key in a pair of cuff links, theoretically.
The engineering is actually one of the more elegant and clever ideas I’ve seen. As we all know, cuff links hold your cuffs closed with a simple bar you rotate out. They also make you look more like James Bond, which in this day and age is really the key function of any set of cuff links.
What Sparrows did was simplicity itself: make the bar hold your cuffs together a standard handcuff key. Just pop open the cuff link, stick the key in the lock, and you’re a free man.
It is worth noting that doing this in front of the police will get you a face full of pepper spray. But as a neat little gift, it doesn’t get any better.
Uncuff Links [Sparrows]