This product works very well for cell, wifi signals, and Electro Magnetify fields caused by over loaded AC power strips.

Note: It did not find a frequency that a neighbor is using to keep me up at night. This frequency causes my body to feel a vibrating sensation with feels like it is causing cancer. I need to find a better meter for that.
I am using a faraday cloth to protect myself WHICH WORKS AWESOME when folded:
https://www.amazon.com/gp/product/B08CRDY392

Works good it has three directional sensors to the front and left right , it gives you a more accurate reading

I purchased this for multiple reasons. I needed a way to at least categorize some RF/EMF/EF fields due to some medical implant concerns. In this case, accuracy was not as important as "relative readings." If the exposure was "X" and a problem occurred, then finding a reading "Y" that resulted in no issue gave a plan of action (welding, HAM radio, etc). What I found was that the meter was calibrated "close enough" for all of my needs. Later when the FCC changed the rules on amateur radio this handy device proved useful in "complying" with the rules over estimates. I have also used this device to better position RF sources away from the kids. No one in my house is RF/EMF sensitive and I do not subscribe to generalized public anxiety over such things. There are unfortunately some that are sensitive and that must be very hard. However, for me it is basically if there is no reason for higher exposure then the meter is a good benchmark. I have used it to also test RF PEP on antennas against SWR analysis and that has proven interesting. The fact I have one device that I can use to measure several parts of the EM spectrum is great.
One thing that I really liked was the support. I ordered this unit over a year ago, and have been very happy with it. However, I decided that over the course of a year there may have been a few software improvements. I sent an email inquiring about any firmware updates from GQ for the unit and had a polite positive answer in about 3 hours. So, I have a device with the latest firmware working as it should. I am now getting addicted to meters. I have this one for non-ionizing radiation... hmmm - maybe I need one of the GMC (Geiger) models now. May wait for a sale on that one as it would be only for "entertainment." RF for the most part you can do something about, background and "event" radiation is another story... ;-)
I would recommend this product, it is useful to see things you may not otherwise realize are there - even if they are "mostly harmless" (come on Hitchhiker's Guide fans)!

Works great for all three emfs

The product is great, sometimes a little bit quite sensitive, but does the job.