This universal equipment mounting plate can be used in a variety of ways. Lidos EXT-01-XL in conjunction with any Lido Mount that has a 4 holes amps face. You can attach any optional holder or adapter to the extension bracket. The powder-coated steel plate measures 13.75” (352mm) long, 2” (50mm) wide, and 4mm thick. It features 120 4mm unthreaded holes that are spaced apart to provide a number of options, including mounting multiple 4-Hole AMPS devices. The four 5mm holes in the center of the plate are recessed and in a 4-Hole AMPS pattern. The 4-Hole AMPS 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).