I have had this lock for 4 years and it has been fantastic. They Changing the app was a small stinky moment because I hate change haha but the lock does what it supposed to do and it loud if someone's messes with it (if you have it on that setting) I used it to secure my expensive scooter and my E bike. Works everytime. Actually I was at the beach once and I heard the Alarm and I saw kids running away from my bike. So that right there sold it 4 times over for me. Also before u forget"¦ the Bluetooth unlock that's neat to.

Suits my needs: to lock bicycle when touring or on local rides when I am never far away from the bike. Lightweight; I don't want to pack around a chain or a big U-lock. Cables are easy to cut, so having the built in alarm gives you an advantage.

You need to understand how it works though. The directions are not well written for English speakers. I almost sent mine back, because the vibration feature (setting off alarm if moved) did not seem to be working. This is because it is designed to not go off when it is blue-tooth connected. In my test this was up to 60' away. So you could be in a coffee shop with the bike locked out front and the alarm may not go off if tampered with. (it should still go off if cut, but I'm not about to waste a lock testing that...) The solution is to shut off Bluetooth on your phone while away from the bike.

It also has a feature option of auto-unlock. This unlocks the device whenever it is in Bluetooth range, saving you from having to pull out your phone to unlock it. So don't activate this if you are going to be closer than 60' from the lock.

[update: I am dropping one star from review because of the vibration alarm feature. It seems senseless to me to have it automatically deactivated while in blue-tooth range. I was told this is so as not to disturb the owner. But since unlocking/deactivating the alarm is done without touching the lock, and considering how wide is the blue-tooth reach, I think that design feature should be changed.]

This is a well made, substantial bicycle lock (or for anything else that needs to be locked up). The directions are another thing, however. For example, "Password change" tells you what you can use for a password, but no where does it tell you how to change the password.
When I first tried to set the lock up to bluetooth, the directions, and what I was seeing happen, did not correspond, so I put it aside to try another day; 2 days later, when I opened the app, it was all set! Now, trying to personalize it is like pulling your own teeth!

Linking instructions made it sound like you could hook 2 different locks on the phone as I ride with a partner. We both got the same locks figuring from instructions one phone could unlock both but you can't. BUT the alarm is very loud and worked perfectly.

This lock is more convenient than the more traditional bike u-locks because you don't need a key. It's very easy to use. While it's not something I can necessarily test, I do feel a sense of security that attempts to cut the cable will result in the alarm sounding.

The alarm, btw, is absolutely ear splitting. Just the arm/disarm notification sound can be painful if you make the mistake of holding the lock too close to your head.

The only feature I wish it had is the ability to have the vibration alert send you a notification when you are outside of Bluetooth range. I do think the auto-unlock feature is essentially unusable; it unlocks whenever you're in Bluetooth range, so if you're in close proximity to your vehicle at any point after you've locked it up, it will unlock even if you aren't actually interested in that result.

Other than that, I can't complain. It's light, easy to store, and easy to use. Worth the cost in every respect, as it gives me peace of mind that my property is secure and that I don't have to fiddle with and keep track of a key.