Seems to have a very poor manual. Tells you how to shut the sound off but nothing else about it. I had to figure out what/when of it myself.
I have a Wixey WR-410 that has a "set miter" option which isn't mentioned or in the pictured item even on their own site, I just asked about that. It simply splits the angle for you. On both Bosch models, you have to subtract the MTR reading from 90 deg. on simple angles. I'm not sure if that's because it will also do bevel angle also or what. At first I thought something was wrong with it.