Special Features:

Front of plate shall be slate gray color with legend obscured except when back lighted

Properties:

A transparent or translucent item designed to enclose or be placed in front of a light source. Sections of the lens may be opaque. It may or may not include a holder. It is designed to be either a replacement unit for a specific type of light, such as light, indicator; light, navigational, marine; stop light, vehicular; and lantern, electric or that portion of a switch, (as modified) used as an actuator and having provisions for illumination. See also, window, lighting fixture; globe; electric light; and filter (2), (as modified).