Use the iBOLT Metal Baker Plate to create a more solid mounting surface when attaching a heavy-duty mount to a soft or porous surface, such as a dashboard. This steel backer plate measures 2.6 inches (65mm) square and features tapped holes in the 4-Hole AMPS pattern. The AMPS mount pattern consists of four holes located in a rectangular pattern spaced at 30.17mm by 38.05mm (measured as the center-to-center distance between holes). Compatible with all AMPS plate Patterns. Screws and washers are included.