In general, I am not enthusiastic about this product. There were no instructions included as stated in the description. However, it's easy to understand after playing with it a bit. There is some information printed on the back about batteries etc, not sure if they referenced that as instructions. I'm not sure if I received a faulty unit, but my measurements were slightly off, so I wouldn't rely on it unless the measurements you took are very important. I have found that I have to measure about 3 times and then double check with a tape measure to be sure. Good thing the seller included an extra battery so I'm giving that an extra star otherwise it would have been a 2 star rating.