PUW (Pforzheimer Uhrenwerke) 61

The PUW 61 is a manually wound caliber produced by Pforzheimer Uhrenwerke in America between 1940 and 1951. Measuring 11½ Paris lines in diameter, the movement contains 21 jewels and features a Breguet hairspring alongside sub-second, hacking seconds, and quickset date functions. Its construction incorporates three-leg shock protection. Approximately 253,000 units were manufactured before production discontinued.