I have one chinese device that I love and have worn almost constantly for 2 weeks now. I figured I'd pick this one up, as it's slightly more enclosed, and had a tear drop ring I wanted to try https://smile.amazon.com/gp/product/B078GJX8C4/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 It's getting returned. The device itself is totally fine - but the locking mechanism is junk. I have 2 others like this, so I know it's this particular one. The key can be partially inserted, and lock / unlock with no problem. These locks aren't supposed to let the key out when they are unlocked, this does. Now, the other two barrels I have fit - they go in, they turn to lock - but the design of this means that they don't turn far enough to release the key - so you can be locked in, but only if the key is in the lock. Thats crappy Fortunately, Amazon have great return policies, so it's going back next week.