By Barr & Stroud, Glasgow & London. 7X magnification. CF23 model. Patented 1940. Monocular with various coloured filters for viewing in different conditions such as haze, mist etc. These are changed via a rotating knob. Also fitted with an extending shower/spray shrouds. The black paint finish is marked/chipped, the filters index reasonably well, and the optics can be focussed at the eyepiece, are spotted/marked but reasonably clear. With the original leather neckstrap and brown leather carrying case, the latter with loose lid and broken straps. Stock code M-Nav.