Outlet Box Drywall Setback Gauge
A flat 120 x 45 x 6 mm step gauge for setting new-work electrical boxes flush with the finished wall. Three notches set the box's projection past the stud face at exactly 9.5, 12.7 and 15.9 mm (3/8, 1/2 and 5/8 in drywall); dimples next to each notch (1, 2, 3) show which is which. Rest the land on the stud, slide the box forward until its rim touches the back of the notch, then nail it, so you don't end up with recessed boxes that need box extenders.
tool electrical outlet-box drywall