Calculated Industries Blind Mark Drywall Electrical Box Locating Tool Kit (4-Pieces)

The Blind Mark will help you get perfect drywall cutouts with no measuring. Just insert the target in the receptacle before hanging drywall. When you're ready to cut the hole, hold the Blind Mark Locator magnet over the area where you think the receptacle is located. When it finds the receptacle, the magnets will snap precisely into place where the receptacle is located. Trace around the locator, cut, then install. With the Blind Mark you simply put it up once, cut the hole and you're done.