Am I glad I bought this?  Oh yeah...now that I know my paper shredder, which sits right next to my desk chair, is creating the highest electro-magnetic field in the house.  The needle spiked up to the highest red level and stayed there.  Scary.  How does one shred paper from a distance? And the simple fans that create a nice cooling breeze?  High.  And the microwave?  Unstable...high, then backs off, then high. I won't be standing in front of it waiting for my hot drink anymore.  But my large plasma TV?  Almost nothing. I had to put the meter up to within two inches of the screen before it even registered.  And my cell phone, surprisingly low.  I like that it has meter levels for different EMF's, electric and radio waves; a replaceable 9V battery; and it's light and simple to use with one hand.  Very glad I bought it.