This is a 7 x 50 Kriegsmarine binocular with device for gas mask use. Special feature: Special oculars with a high eye relief. For normal use the eye cup ( the top is made from rubber) is pulled up. (last picture) For use with a gas mask, the cups are pulled down.( 3th picture) Diameter of the eye lens is 23 mm. Aluminium body, black rough colour coat. Graticule in right-hand side with vertical and horizontal graduation. This glass has coated optics and excellent performance.