Good product but as with all them you need to experiment or trial on known surfaces to get used to it with confidence. A lot cheaper than most competitors
It is a very handy tool.
It finds every metallic particles and live wires.
I have to calibrate each time using it and then it shows the cables.
It is very useful for DIY.
Funny thing, since haemoglobin and myoglobin is full of iron it will find metal in yourself too.
If you are after something more detailed, like depth of cable etc for professional use, this is too simple and you will need to pay much more.
For an average household it is just perfect