Hamilton, early 4992B, United States Military Navigational Master Watch GCT, 22 jewels, adjusted six positions. 16 size. Serial number is 4C113037 (circa 1952.  Hack setting (stem pulls out to stop second hand). Dial and movement are excellent. Case is in good/very good condition with some signs of use.  Crystal has one scratch on right about 5 o'clock; remember it's a 24 hour dial. These watches were issued to navigators and pilots during World War II and thereafter. It has a 24 hour dial and was intended to be set to Greenwich Civil Time (GCT).