Consigned by a private collector.

Reference 3941 is possibly the rarest variant of the yellow gold 3940 self-winding perpetual calendar wristwatch series. In fact, since the launch of this model family in 1985, only a handful have returned to the market. Since the glazed backs were not numbered, Patek Philippe chose instead to apply the case number inside the upper case part, underneath the bezel.

Production of references 3940 and 3941 was launched in 1985, the difference between the two reference numbers being their backs:

- ref. 3940: plain snap on back
- ref. 3941: glazed snap on back

To respond to their customers increasing demand for two backs, Patek Philippe produced the model as of around 1988 with both the plain and the glazed snap on back. Consequently, production of reference 3941 was discontinued in 1990.

The model is illustrated in Patek Philippe Wristwatches by Martin Huber & Alan Banbery, second edition, pp. 292 & 293.