Marquee Sign Boxes This bright backlit system with flashing bulbs makes advertising easy. All durable extruded aluminum construction black painted finish, with snap frame graphic holding system and plastic diffuser. Ideal systems for movie theaters, video rentals, shows and other special events. Simply open the spring loaded snap frame on all four sides in order to insert or exchange graphics. Indoor application, C.S.A. and U.L. certified. Available in single sided or double sided formats. Note: Double sided boxes will only have flashing bulbs on one side.