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

 

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!