Let me start by saying these little alarms are LOUD. Like, 'wake-the-dead-and-scare-the-neighbors' loud. The 95 dB alarm is no joke – when it goes off, you'll know immediately if someone's trying to sneak in.

The installation is super simple. Just peel and stick the magnetic sensors on your door or window frame. No tools needed, though you'll have to supply your own AAA batteries (annoying they're not included). I put mine on both windows and doors throughout my apartment.

Now for the not-so-great parts... The adhesive is weak sauce. Half of mine fell off within a week, especially on slightly textured surfaces. I ended up using stronger double-sided tape which solved the problem. Also be warned - the alignment between the two sensor parts is finicky. Get them too far apart and you'll get false alarms at 3 AM (ask me how I know).

Weirdly, not all units have the same alarm tone - some sound like a dying robot even with fresh batteries. But hey, at $2 per alarm, you can't expect perfection. They do their main job well - making an ungodly noise when triggered.

Best use case? Temporary security for renters or as backup during power outages when smart home systems fail. Just don't rely on them as your only security measure unless you enjoy re-sticking fallen sensors every few days.