Swiss. 18K white gold case and clasp. 36mm case diameter. The reference 3940 is undeniably one of the most iconic perpetual calendar wrist watches available today. It is predominantly found in yellow gold, with far fewer examples in 18K white gold, as the example offered here. Features presentation caseback with optional 18K gold caseback. Signed on the case, movement, dial and clasp. The watch is currently on a replacement leather strap. The original leather strap with 18K deployant clasp is included, but the leather is worn. Includes original presentation box, sales literature and Patek Philippe "certificat d'Origine". Originally purchased on August 12, 1999 from Tourneau in New York. After winding, watch was found to be running at the time of cataloguing, however, it has not been tested for timekeeping accuracy. No known service history is available. CODE:WAT