Does the job and is a little cheaper than other options. What I can't figure out is why the nail on the bottom won't come off. I don't always want to put holes in my wall to let the thing spin. Sometimes (most of the time) I just want to get the level reading and spread it evenly across the wall so I can mark it with a pencil. The design of this thing is that you have to unscrew the bottom nail and drive it into the wall. Failure to do this will result in the nail not sitting flush against the unit and preventing the unit from sitting flush against the wall even during leveling work. . This makes it useless as you cannot rely on leveling bubbles. break nail You'll be glad you did. After that it works like a charm. However, such a flawed design deserves a mention.