Traditional stainless shore power inlet has gasketed, self-closing cover so that the interior is shielded from the elements when not in use. It is watertight when the cover is securely fastened. The mounting holes are 23/8" (60.3) on centers, and the rear portion has a 2.171" (55.1) diameter. Mounting screws and gasket are included. IP56 SUITABILITY.