Korect-A-Bore provides an easy method for enlarging a cross bore hole when you’re replacing a particular manufacturer’s lock with another manufacturer’s, where a different size cross bore hole diameter is required. It is ideal for changing the backseat on a cross bore hole from 2-3/8" to 2-3/4" and vise versa. The perfect tool if you have to enlarge, move, or rebore a misaligned cross bore hole in a door. Korect-A-Bore assures of "truing" a hole properly so that the replacement lock you install will fit perfectly.