Generally, Ajax are top-notch, but even though I set it to high sensitivity, it goes off with smoke; I just think not that easily.

For example, with a cigarette, you have to place it exactly underneath.

You can also check the device from the app, and it shows up as okay.

Beautiful design, easy installation, activation, and connection to the application. Tested with smoke from burnt paper and immediate notification with siren

All the Ajax Systems I purchased are working perfectly so far and I am very satisfied.
The only possibly negative (insignificant) thing is that it does not have an option to adjust the siren volume, and since it is in a small space, it sounds excessively loud.