This is one that you RARELY see anymore, a Hamilton 16 size, 22 jewel, open face, 3992B Navigation Master in excellent condition. It has the correct 3 tiered dial 1 to 12, 1 to 60, and 1 to 10 also in excellent condition. It has the GREAT looking ¾ hack movement signed “Adj. Temp. And 6 Positions, 22 Jewels, U.S. BU Ships, 3992B, Hamilton Watch Co. U.S.A.”. It comes mounted in the original SB&B base metal case with the usual markings on the back. A REALLY FINE EXAMPLE OF MAYBE THE BEST MILITARY WATCH OF IT’S TIME. SN 3C757 Ca. 1942.