Very well preserved example with the smoothest running second hand there is. Our favorite tuning fork f300hz Constellation. The very high frequency gives the seconds hand a flowing motion. Holding the watch to your ear, you will hear a summing tone. Therefore these watches were called “hummers”. This example has a beautiful silvered two tone dial with applied hour markers. At 12, there is a prominent red framing of the Omega logo serving as the “12” . All the luminescent material is intact, and the hands have only a minor lume degradation. The red seconds hand match the red logo/hour marker at 12. The Omega movement in the f300hz series of watches was licensed from Bulova & ESA. The base of the movement is stamped ESA 916, the Omega caliber being 1250. Case manufacturer is CB. Omega case reference number is 198.0006. This model uses a Renata 344 batter. The case size is a slightly larger 36mm case diameter than was to be found in the earlier Constellations and dates from ca. 1972. The original and comfortable Omega bracelet has reference number 1177/17 and has 14 links. It will fit a wrist up to ca 18,5 cm.