First, let me clarify that I am a carpenter. If you work with doors like me and deal with pocket doors and mortise locks on a regular basis, get this tool. If you're just doing this for yourself and need to install a lock, take a shovel, chisel, mark lines and hope you don't have to poke through the side of the door. For me it was a game changer. The time and effort savings are enormous. Once you get used to the setup, this is just the way to make mortise lock installation quick and easy. Watch