Secure Scan PMD38 Metal Detector

I ordered this because my dogs took a wireless meat thermometer out in my backyard and I couldn’t find it. I have a huge backyard. Anyway, I got this, hoping to find it. At it’s normal setting, it is way too sensitive. I’m between 5’3” and 5’4”and I can hold it above my shoulders and according to it, my entire yard is full of metal. It beeps constantly all the way across my yard. When I put it on the low sensitivity, it hardly beeps at all. When it does detect metal, it’s because it is touching it, but I put it on nails on my fence and, more than not, it did not detect them. Also, to use the low sensitivity mode, you have to hold the button down the entire time you use it. It’s you let go, it reverts to the normal mode. It comes with a holster so you can wear it on your belt but if you use it, it will not hold up long. It’s very cheaply made. It comes with the battery. It says it can also be charged, but it doesn’t include a charger and I don’t see where it says what kind I would use. I didn’t look super hard since it doesn’t work.