Brushed aluminum single locking receptacle cover plate. Single flip lid cover for 20A or 30A single locking receptacles. Device opening is 2 5/8'' (67mm). For use with maximum female locking device of 1.58'' diameter, and maximum male plug face of 2.25'' diameter. NOTE: Brass covers and flanges are not interchangeable with aluminum or nonmetallic covers and flanges. Nonmetallic covers are interchangeable with aluminum flanges.