Here is a interesting item I picked up a few years ago. According to the manual, photos and box, it is a gyroscopic gun site for the US Navy 20 MM and or 40 MM Antiaircraft guns. It is in spectacular condition and came with a 2 instruction manuals and a technical manual. The cool thing is the way the oporater manual was written. It was writen so a child cold understand. Very simple, to the point with great associated visual diagrams or photos. I took a few pics. I am sure a few of our members have actualy fired these weapons while using this site. Hope it is not concidered off subject?