Have not even bothered to use it, just returning. It is supposed to "lock" into place to give you a 90o cut guide, but the alignment holes are off for the dimples that are suppose to fit in the holes, so it never "locks" into place. The only way I would trust that is was square would be to use a right angle to check for square. Mine was hard to set at 90o using just my hands (does not rotate smoothly). However, when using it, it would be easy for the saw to push it slightly out of alignment because there is no way to lock it at a set angle.Elimination of the 90o alignment holes/dimples and the addition of some kind of real lock that was accurate would be good.