This monocular microscope from Carl Zeiss was manufactured under No. 151,728. It is an extraordinary microscope because, although it is an instrument designed for work, it incorporates all the advances described up to then and is manufactured with extraordinary quality.

All the optical part is made of brass and the mechanical part is enameled in black. His revolver has four targets. Its micrometric focus is graduated. The stage is circular and with extraordinary mechanics, it allows rotational movements, having the BBT Krauss-type overplate with graduated scales to measure displacements. Finally, the condenser is also very complex allowing the displacement of its parts. Santiago Ramon y Cajal (1852-1934), Nobel Prize in Medicine in 1906, was an enthusiastic user of this model.