If you think this, it will effortlessly provide you with accurate angle measurements (like my husband), you will be surprised. You still need to use the formula to subtract 90 from the reading to get the correct angle. The manual is very limited in what it explains. This is nothing for a beginner. But once you get the hang of it, it works quite well. Not sure of the long term accuracy or how well it will hold up as we haven't had it that long.