Some of the most useful advertising positions are the wrong shape for a normal screen: the edge of a shelf, the strip above a counter, the header of a fixture, the space over a bus doorway. A stretched bar display is a long, narrow screen made for those places.
Stretched Bar Displays (view the range) are listed in sixteen sizes from 19.5 to 80 inch, at 300 or 700 nits, in black or white, as wall-mounted units or as open-frame versions for building into a fixture. Playback options are listed as HDMI input, Android or Windows. The aspect ratio and resolution differ from size to size and are confirmed for your configuration.
Because the shape is unusual, content is the thing to plan. A price strip, a scrolling message or a run of product images works well; a standard advert will not fit without redesign. If the strip needs to show prices or availability from another system, that is a software integration to scope. Digital signage content management is quoted separately from the hardware.