I really like this tool. The display is big enough to easily read and it was calibrated when I received it. Thinking about buying a couple more.

I think it works well I've been analyzing the effectiveness of my flowhood with and without the house ac running. I have side panels for my 2x4 and I was able to confirm that the flowhood's sterile feild was extended some. The feild was pretty small on my Lrfh

 

When I first thought about buying this, I figured it would be very flawed, especially since most similar particulate meters are hundreds to thousands of dollars in cost. But it had been recommended by someone who's opinion I valued. Then when I received and first tested the meter, it read 0 throughout my growing area, which I knew was improbable (or impossible), so I shelved it. several days later I used it in a very debris ridden garage and the readings reflected it. So I took the meter back home and retested my growing area and now the readings were realistic: 0 in front of my laminar flow hood, but gradually increasing in particulate as I moved away from the hood. If I had the hundreds to thousands it would cost for a MET ONE laser, I would buy it. But for an inexpensive alternative, this one seems fine.

I was looking for something that would read super low micron that was under $100 and this is perfect! I just received and my room without my flowhood is Dirty As Fu*k. I will report back after I run it for a few hours. Great little device

Came with easy to follow instructions and a link to a video tutorial, very straightforward and easy assembly. Arrived very quickly too!