Made of wood and metal, The fanciness on the metal top is shown bellow:

U&U trademark + patent (copyright) June 11 1901

The stereo effect is based on 2 lenses with the exact distance between both eyes. To focus: the stereoview is moved back & forward. The picture is created/taken by a setereo camera which has 2 lenses in the same distance between them. One shutter-release takes both pictures from those points of view just like our eyes.

U&U was one of the largest publishers of stereoviews and viewers (later  purchased by Keystone company)
Click here for a list of early photographers & publishers of Palestine (U&U too)