I'm not sure how accurate it is or isn't. It reacts to the filters, for example, or if I hold it in front of the filter it'll reach a very low number, conversely if I take it to other parts of the house or outside it'll increase. I've done a few trials like that and it seems directionally accurate, but I can't speak to the numerical accuracy.

It measures PM 2.5 and 10 and has a button to show graphs over time for ~12 hours. Battery life is pretty good, I usually leave it detecting on the charger, but I've had it in handheld mode for several hours and stayed above 80%. It's super simple to use.

One thing I don't like about it is that it has a cheap plastic hinge that is supposed to let it stand up, but it broke on me after a couple uses. It doesn't seem to matter though if it's standing up or laying down, it still reads pretty much the same.

I wish it had a way to export data to my computer or maybe an app.