Hamilton Chrono-Matic "A" Caliber 11 Automatic Panda MOVEMENT_507 Electric and the balance had poising

and the balance had poising screws rather than the stamped brass balance used in the 505 (see page 80 in Rene's book)

Information can be found on page 201 of "The Watch Of The Future

BAND:  Brand New Original Band

SIZE:  29mm without crown | 39mm lug to lug

Hamilton Chrono-Matic "A" Caliber 11 Automatic Panda MOVEMENT_507 Electric and the balance had poisingOffered is this stunning Hamilton Chrono Matic "A" with world's first automatic chronograph introduced in 1969. The watch is Fully Serviced. It winds, sets, and runs great. It keeps excellent time, and the chronograph feature works flawlessly. The Caliber 11 was a collaborative effort between Hamilton, Heuer, Breitling, and Buren. Each company released a version of this movement, and it can be easily distinguished by having the winding setting crown