I saw this advertised in a tool catalog ten years ago. I kept thinking I should buy that, it is a good idea, I hang a lot of doors, and that would save time and make my radius jig cuts clean right up. I remember the torment I felt when I would cut a corner off square, too vain to fill it, I made painters come behind me and make me look good. Not any more... I am now perfect with my perfect corner maker. Buy it now don't wait the ten tormentuous years I did.