The Patek Philippe reference 3940 was first released in 1985 in a limited edition of 25 pieces made specifically to commemorate the 225th Anniversary of Chronometrie Beyer, a Zurich-based retailer and long-time friend of the Maison. The first 25 models were numbered, with the dials stamped with Beyer and their series number. For its release, the timepiece was only available in yellow gold and was later made available also in pink gold, white gold, and platinum.

Highly complicated and visually striking, the timepiece is made alive thanks to the ultra-thin automatic perpetual calendar movement caliber 240Q. A triumph of micro-engineering from Patek Philippe, it was one of the smallest and thinnest movements on the market at the time coming with a Geneva seal. At 36mm in diameter with a slim circular-shaped case the timepiece is extremely comfortable and elegant on the wrist.

The present example of reference 3940R features an attractive and captivating early version within the second series dial. These series dials featured ‘beveled’ sunken sub-dials at the 3 and 9 positions with the Sigma position remaining below the outer track. Furthermore, it is noticeable that the Patek Philippe signature is slightly enlarged compared to the 1st series however the sub-dial font remains the same. Similarly to first series 3940's, early second series can be found with the original solid caseback, like the present example, or a requested sapphire caseback.

Preserved in excellent overall condition, with the 24-hour sub-dial that has developed an attractive warm patina, its vintage charm, slim aesthetics and historical importance will certainly please any collector of new-vintage wristwatches.