The Feldglas 08 6x40, was manufactured between 1916 and 1918, with around 4,000 units produced. This version had 40 mm lenses, 6x magnification, and a robust die-cast metal body. Its design included separate focusing eyepieces, diagonal knurling, and adjustments that increased weight and dimensions compared to earlier versions. Features indicating its military use included a large hinge clamp diameter, an interpupillary distance scale, and loops for a neck strap.
The binoculars were marked with “Carl Zeiss Jena,” the model name “Feldglas 08,” a serial number, and a military acceptance stamp (“K”) from the Gewehr-Prüfungskommission. A probable production date of April 1917 is also inscribed.