Abstract: An access control system for preventing access to underlying fasteners, and otherwise preventing tampering with the underlying control panel. A base plate is affixed to a base that is fastened to the underlying structure with standard fasteners. A cover plate is slidably disposed over the base plate and includes a key operated cylinder plug. The cylinder plug is inserted through the cover plate, base plate and into a receiving aperture in the base. A locking mechanism within the cylinder plug engages the base, and prevents the sliding disposition of the cover plate from the base plate.