Kreg KHI-HINGE Concealed Hinge Jig. The concealed hinge jig takes the guesswork out of installing cabinet doors using concealed hinges. This economical, easy-to-use jig ensures accurate hinge alignment, so you can install doors that fit great and work well. Reliable drilling with bit guide and stop collar, simple to use with any drill and requires no special tools, adjustable cams ensure proper hinge offset, plus more.