I can't rate it as a construction tool. I took it to measure the focus distance for working in cinema with a movie camera. He coped with this task perfectly. If you are a magician then take it))) Zero point on the back of the device. Its pros: Small and cool design. Can be carried in a pocket or around the neck on a ribbon. It weighs almost nothing. Has cons: It seems to be all right. It seems like in the characteristics it was indicated up to 40 meters, but in reality after 25 it doesn’t really measure. It is small and it is both an advantage and a disadvantage is easy to lose.