Bausch & Lomb Optical Company, Rochester, New York 1897-1903
The Unicum Triplicate has also been referred to as the Stereo Unicum. This example, with a Rochester Optical & Camera Company badge, dates it to approximately 1899-1903.
Although the mono version of the Unicum - Model of 1897 would continue to be manufactured until at least 1908, it's not known how long the stereo version was offered.
Despite mono versions of the Unicum- Model of 1897 being quite common, the Unicum Triplicate is rare. This is the only physical example I have ever encountered.