The Omnium is the fourth stereoscope in my collection that comes from the range of Lucien Bize and his successor Robert Pleyau. This model is only intended for viewing stereocards, but there were also models with a frosted glass to view glass stereoviews. All of Bize's stereoscope designs were extremely compact and the Omnium is no exception.
The stereoscope comes with its original burgundy colored box. The viewer is collapsible and the handgrip can be unscrewed from the viewer part. Focusing is done by a knob on the bottom that slides the stereocard holder forwards or backwards.
Little else can be said about this simple viewer. I only bought it to complete my collection of Bize stereoscopes and because of the original box, which is often missing or in poor condition.