As usual, Kub have come up with yet another brilliant reproduction of a truly ingenious design.  Forget your usual conventional key, they are opened with a simple metal key that just slides through a slot and pushed back the catch, a bit like using a credit card to open your lock on your front door!

When fully folded the mechanism is disengaged, consequently you can upen the handcuffs fully without the key.  Open them up to use on a prisoner and the lock mechanism works perfectly and will not open without the key.

The internal circumference is eight inches and they weigh 560 grams (roughly 1lb 4oz).  The picture shows the handcuffs in the open position.