Although the level glass can be accurate, the base doesn't help. look at my photo, the body of the liquid sits on the base, i'm totally disappointed. I had to disassemble it, file it up to adjust the gap. It then needs to be recalibrated, and that's even more of a hassle than you would have to do it from a "quality" place like Starrett. then I found that if I rotate it 180d the bubble is in 2 different positions, WtH? I should have just returned it.