The KDFITTINGKEY is mortised into the back of a picture frame or shelving unit.
The KDFITTINGKEY then is slipped over the head of a #12 round head screw (not provided) and therefore there must be room mortised for a screw head to project into the unit. The wedge shape provides a pressure fit against the screw. Plate is 5/8" x 1-3/4" x .125".