I've used these touring a lot. I cannot attest to how strong it is or how long it can delay a dedicated thief. What I like is the foldable design that makes it compact and easy to store. Also its long enough to get around poles I can't reach with the U type locks. I got a second one for my wife. So far so good.
A great and compact alternative option to the common U-lock. It does seem to be unbreakable.
