Editing Handcuffs (section)

=== Double locks ===
Handcuffs with double locks have a detent which when engaged stops the cuff from ratcheting tighter to prevent the wearer from tightening them. Tightening could be intentional or by struggling; if tightened, the handcuffs may cause nerve damage or loss of circulation. Also some wearers could tighten the cuffs to attempt an escape by having the officer loosen the cuffs and attempting to escape while the cuffs are loose. Double locks also make picking the locks more difficult.

There exist three kinds of double locks as described in a Smith & Wesson brochure:

;Lever lock: Movement of a lever on the cuff causes the detent to move into a position that locks the bolt. No tool is required to double lock this type of cuff.
;Push pin lock: A small peg on the key is inserted endwise into a hole to engage the detent.
;Slot lock: These also are actuated with a peg, but in this case it is inserted into a slot and moved sideways to engage the detent.

Double locks are generally disengaged by inserting the key and rotating it in the opposite direction from that used to unlock the cuff.