Definitely works well. This is not a retractable box to use the device. I had to read the instructions to find out what the different screen displays mean. After it was done, it was a breeze! It recognizes really well and is very accurate. For the $20 price I paid. I can't ask for more. And the visual ability to see how close or far you are from the center of the hairpin is ideal. I highly recommend it to DIYers like me.