A folding metal viewer for stereo cards included as premiums in packets of Army Club cigarettes. There were nine series of views in black and white and two in color. Most of the views were on separate cards, although there were sets with both views on a single card (Middleton 2021).

There are a number of versions of the viewer. It was first introduced in 1920s Germany as the Stereo Indupor. The Swiss patent (CH90740A) emphasizes ease-of-use as the key goal: both the focus and interocular distance are fixed, the viewer is easy to fold up, and once folded fits easily into a pocket (Stereo-Indupor 1921).

Cigarette cards started in the late 1800s as blank cardboard stiffeners for paper cigarette packs. Manufacturers quickly realized that they could be printed on and offered as premiums. They died out following World War II (Johnson 2026).