I really like it so far.
It fits nicely tucked away under my seat post.
It is quite loud. Loud enough that I haven't really tested the full alarm all the way.
I often forget that I set the alarm and then I grab something out of my pannier bag and I get a quick , double warning alert. It's loud enough that I IMMEDIATLY stop what I'm doing and grab the keyfob lest I annoy my neighbors or townsfolk.
(minor drawback is the sound of setting alarm or unalarming the device. It makes a pretty loud and distinct tone to let you know it has been alarmed/unalarmed.)

I hate thieves so making harder for their way of life is a priority. I placed one of these on the trip-fold cover on the bed of my truck. Simply used industrial strength velcro to attach the alarm on the panel closest to the bed on the inside. Either the motion of them trying to force the cover/tailgate open or the actual opening of the panel sets off the alarm. Granted since it is held on with velcro they/them could pull it off but that initial noise resonating inside the bed will draw some attention. We also use these on our e-bikes. All sorts of uses for these. I imagine you could put it on your garage door if you had a need for that. Scumbags look for easy targets that's just they way they are.

This has to be one of the best things I've ever bought from Amazon or anywhere else for this price or for the purpose it's used for. First of all to the seller this should be advertised for more than just a bike alarm you can really use it for anything from a backpack to a scooter to anything that somebody could walk away with. It is built super well super easy to install the remote control is like a remote control for a car it is durable it is sturdy it is amazing I am so impressed with this I'm going to order another one just to have a backup but I'm sure I'll find a use for it. It's terrible that nowadays we even have to think of having an alarm put on our bicycles but a lot of bicycles today that are locked up are have nothing left but a frame or whatever they could take off the bike and walk away with this this alarm is so sensitive that I have a a saddlebag on my bike if I just open a zipper without deactivating the alarm it sends a brief message that alarm is about to go off and then it does this is a great great product for the money don't even think twice about buying it by two by three you will finally use for it thank you seller this is an amazing product. It is very loud...500 STARS

In my apartments garage, where most of my items have been stolen, this little device makes a great startling noise that i can hear even from my apartment. I feel better knowing I could be alerted to prying grubby hands trying to tamper with bike. But now that I chain my bikes together with my trailer and some of its locked anckored contents, Im feel good knowing that even a distant object to my bike will trigger this alarm and alert me to tampering. I just need to find the perfect location to mount this alarm so its not easily snipped off, but between this loud little device, a hidden airtag, and 2 thick locks well placed on my bike, all secured to other items, I've been sleeping better at night knowing an extra level of security is in place.

This product will definitely scare any would be thieves and give them second thoughts about stealing your bike. Most the time I use it I forget to turn it off before I begin the process of taking off my locks and when I grab the first lock it lets off it's warning sound and scares me to death. Solid product, super loud. I can hear it from my connected garage 20-30 feet away while I'm watching TV in the living room.

My only complaint is that it's so loud that sometimes I deactivate the alarm when I'm right next to it and it hurts my ears. But I think that's just a testament to how loud of a product this is. I just wish the deactivation sound was a little quieter.