Original pre war RK31 aiming circle with an original leather case. The optics are clear, the levels are working, the compass points north (and south) and everything turns freely and smoothly. There is some wear in the paint, which you can see in the photos, and the leather case is in pretty good condition, even if it shows its age a bit. Its been around the block a few times and can do it many many more. An all around good example.
This would have been used as the primary sighting device for battery fire. Basically this would be used to determine the direction and inclination etc... and then used to provide corresponding firing data to the other guns relative to their position to this aiming circle. The sights on those guns would then look back at this aiming circle to properly lay the gun. It is a process that makes perfect sense and sounds more complicated than it is. Used for most indirect firing, such as mortars or artillery, although during the war they started using one of the gun sights in place of an aiming circle as these became more difficult to supply. The gun sight lacks some of the functionality if the aiming circle, but could still work for most scenarios. This would normally require a small tripod and was generally used with a little periscope. It is a fine precision instrument.
