Review on VIVREAL 4 In 1 Stud Finder Wall Scanner With LCD Display - Center Finding Beam Finder And Sound Warning For Wood, AC Wire, And Metal Studs (Black/Silver) by Jon Russell

I bought this stud/line detector in preparation for an electrical rewiring job I'm going to take on in my house. The detector seems to work well given the price, but there are some caveats I've found while using it.#1) Try to do the calibration in an area of the wall where you know there are no studs or electrical. Although the instructions state you can calibrate anywhere, I've had best results calibrating over an empty wall cavity.#2) Do not move while calibrating the unit.#3) When doing scans, make sure you move slow and evenly over the wall surface. I got best results when moving at about 1" per second (pretty slow).#4) Hold the detector in the same orientation as the framing member you are trying to detect - up and down for studs, and horizontally for blocking.The electrical wire detection is ok, but like any detector of this kind, you will need to move slowly, and scan multiple times because the detection is not always repeatable.One thing that could have been improved is if there were some way to lock the unit "on" for detection. There is a single button that needs to be held down for 3 seconds to calibrate, and KEPT down as you scan. I found my finger getting tired cause some of my scans were pretty long.