Seikosha Chronograph pocket watch from a WWII type 89 Konishi Rokuoh-Sha training machine gun camera. These training cameras are rare, and even more rare are the watches that were mounted in them. These cameras almost always are missing the watch or have the incorrect watch mounted in them. This watch is about 44mm in diameter. It does run, but has a very slow beat. Likely a good cleaning and oiling with remedy this. Mainspring is wound tight. Chronograph function works as it should. seems a little gummed up though. Missing the crystal and has old tape residue on the case. Look at the photos for the best description.