Over the last 30 years I've used several other stud finders, including brands like Zircon, Strait-Line (now Irwin), etc. This is easily the best one for quickly and accurately finding studs behind drywall. I got fed up with "Calibration Errors" trying to get readings from my previous Strait-Line one (which is now headed to the landfill). No such problems with this unit! Pros: - Comes with a 9V battery installed, ready to work once you extract the unit from the ubiquitous clamshell packaging. - No On/Off switch...it only goes On when you have the left-side switch pressed in. Result: No annoying battery drain issues. - The LEDs are nice and bright and visible in strong daylight, and give you a good idea of what lies underneath. The projecting "spotlight" LED is genius. Cons? - Not too sure about the AC hot wire detection. I would not rely totally on the accuracy of it myself.
Our house is the most basic construction you can get: drywall over 2x4 studs, and all we want is an accurate indication of where the studs are. That's exactly what this tool is supposed to do, and it completely fails at its most basic function.
I am pleased with the results of the stud finder. it did the job that it was intended for.
I used it to find studs and it worked ok.
I then used it to fine joists in the ceiling and it was not satisfactory.
I will recommend this to a friend with this comment.