Well, I posted the grand dad's DuoPlan a while ago, and we just discovered he bought his wife one too, now we also have it. Dennis encouraged me to post them. These are very small watches by today's standards. The women's watch has the smallest movement ever made. They were designed in two planes to make the balance, etc., larger and gain "large" movement accuracy. Predated 21,000 by decades, too. Sweet watches by any standards in my book, amazed to have them... Hers is an Astrua mark--an Italian jeweler--but 100% JLC. They were living in Turin in the 30's when these were purchased. Nice for that special occasion. Someday small will be back, too! The ladies movements were made into the 60's, but only 2,000 total. That case is pretty special, though.
David

 

These are VERY cool watches. The lady's watch that was the smallest mechanical movement was the caliber 101, and the 21,600 bph was way ahead of it's time as the rest of the industry didn't get to that fast of a beat until the late 50's and it didn't catch on until the late 60's or 70's.