Carl Zeiss Jena DF 7x40 binoculars, which were standard-issue service glasses for the East German NVA (Nationale Volksarmee). Key Features and History • Military Design: Introduced in the 1960s, these were the first binoculars Carl Zeiss Jena built from scratch after WWII. They are highly regarded by experts for their robust, armored body and exceptional optical quality. • Optical Specs: They feature 7x magnification and 40mm objective lenses, offering high twilight performance. The design includes a five-lens element ocular construction for long eye relief, making them usable even while wearing a gas mask. • Specialized Tools: Many units include a ranging reticle for distance estimation and an infrared detector window. • Durability: The body is protected by thick rubber armor, and the unit is designed to be waterproof (immersible up to 1.5m) and functional in extreme temperatures. • The red circular element is a passive IR detector. In a military context, this allowed soldiers to detect if they were being illuminated by an enemy's active infrared searchlights or signaling devices • These units typically needed to be "charged" by exposing the red window to a light source (like sunlight) before they could function • The serial number is 3794387. • Based on Carl Zeiss Jena production records, this serial number indicates that was manufactured in 1968 produced at the height of the Cold War for the East German NVA (National People's Army)/ Models from this era are prized for their heavy-duty construction and high-quality optical glass, designed to withstand rigorous field use. Has a weight of 1279 grame.Lens are clear and is all full functional. Condition: see also the pictures, they are part of the description.