This pocket microscope started off looking quite useable for the price, but after using it for a while found that if held at a certain angle the lense just falls to the bottom. The only thing you can do is hold the wheel that focuses it, but one slip and you have to refocus. I dont think the unit is faulty, its just the way its made. It feels solid, and the build of it is adequate, but this problem makes it very tricky unless your using it standing straight up. I would suggest paying a little extra and getting something better made.