In a perfect world every corner in a room would be a perfect 90° angle. Anyone who’s ever installed crown molding in an old house knows it’s not a perfect world. The Magic Mitre helps you make custom inside and outside mitre cuts for odd joints that would otherwise require some fudging.
You adjust the Magic Mitre’s adjustable template to fit against the angle that’s being cut for, then lock the template into the workpiece holders. You don’t need to take any other measurements. After the device is locked in place and the template is removed, you can make a perfect cut for the corner being worked on.
Though it’s definitely an “AS SEEN ON TV” gadget, it could save your sanity if you’re pulling your hair out refinishing an old house. QVC.com offers it for $54. Street pricing is as low as $20.