The M-2 compass was used by the US military to direct artillery fire and orienteering. The compass is the military version of the Brunton Pocket Transit and was originally issued in the case,carrying, M-19. The case is also embossed with D-82645; neither the metal snap is nor the belt loops are present and the leather a little dry. The compass is made of cast aluminum and, excepting the magnetic needle and needle pivot, other non-magnetic materials. Scale markings are in mils: 6400 for azimuth and 2400 mils for angle of site (1200 mils each way). There are two bubble levels under the glass cover and the needle pivots on agate housed in a jewel housing. The needle lifts off and locked away from its pivot point when the cover is closed. A mirror with an etched black line and sight hole is located in the instruments cover. Front and rear sights have pivoting tips to allow precise sighting. This piece is in great shape: mirror and etched line, cover glass, interior marking, all moving parts work, compass needle is raised, locked and lowered as advertised, bubble levels clear. The identification plate riveted to the exterior of the mirror cover is missing and exterior finish has ware as shown in the photos. Considering this is a historical item, perfectly suited for immediate use (probably orienteering rather than calling in artillery fire, but...)and a new Brunton ComPro (composition body) or Conv Pocket (aluminum body)run about $350 to $480, this piece at $250 ought to sell fast. It has a ton of patina and character and is really a great piece for us people who like moving things we carry and use in the outdoors! Although I listed Brunton as the manufacturer, I do not this is true. It would have been manufactured under U S Gov't contract and Burnton would have been the obvious choice.