These are unused in the original military packaging dated 1951. These fit with our B1071 (although they are almost gone) and are made to be used on the M71 military telescope. 190mm long, top diameter is 42mm (ID) and 47.5mm (OD). Both sides are threaded. The bottom diameter is 35mm (ID) and 39mm (OD). The objective inside is coated with a diameter of 40mm and a focal length of about 95mm.