• cal. CH 27-70 Q. lever movement, stamped with the Seal of Geneva, 24 jewels, Gyromax balance • silvered dial, applied yellow gold faceted baton indexes, baton hands, chronograph hand, subsidiary dials for constant seconds combined combined with 24 hour indication, 30 minute register combined with leap year indication and date combined with moon phases, twin apertures for day and month in English, outer minute track • 18k yellow gold case, concave bezel, screw down sapphire crystal display back • case, dial, and movement signed • with an 18k yellow gold Patek Philippe folding clasp

CASE Case in very good condition with light wear and some oxidation consistent with age and use. Some very light surface wear to the bands and lugs overall. Under close observation, some very superficial surface lines. Buckle with some light scuffing and wear. DIAL Dial in excellent condition overall. Some very light wear to the engine turning of the constant second and 30 minute register. MOVEMENT Perpetual calendar, chronograph, indicators, and moon phases working properly. The movement is running at time of cataloging, however it was not tested for the accuracy of time or duration of the power reserve and may need service at the buyer's discretion. Please note that Sotheby's does not guarantee the future working of the movement. ***Please be advised that the bands on this watch are made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) and thus not sold with the watch, they are for display purposes only. We will remove these bands prior to international shipping.***
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. All dimensions in catalogue descriptions are approximate. Condition reports may not specify mechanical replacements or imperfections to the movement, case, dial, pendulum, separate base(s) or dome. Watches in water-resistant cases have been opened to examine movements but no warranties are made that the watches are currently water-resistant. Please note that we do not guarantee the authenticity of any individual component parts, such as wheels, hands, crowns, crystals, screws, bracelets and leather bands, since subsequent repairs and restoration work may have resulted in the replacement of original parts. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. In particular, please note it is the purchaser's responsibility to comply with any applicable import and export matters, particularly in relation to lots incorporating materials from endangered species.NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

**Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping."

Accompanied by a Patek Philippe Certificate of Origin dated June 20, 1998, and an Extract from the Archives confirming date of manufacture in 1998, and date of sale on April 16, 1998. Together with one additional solid case back, booklets, one bi fold, and a presentation box with outer packaging.  Reference 3970 was created following the success of the exceptional and iconic Ref. 2499. The design of the case of Ref. 3970, with its down turned, fluted lugs, is clearly influenced by the form of the Ref. 2499. One main difference between the two models is the addition of the leap year indicator to the 3 o'clock subsidiary dial and 24-hour indicator to the 9 o'clock subsidiary dial. The firm's collection of perpetual calendar chronograph wristwatches is highly desired by collectors and represents the firm's superior horological expertise.
Patek Philippe first launched the Ref. 3970 in 1986 with a snap on case back. Two years into production, Patek Philippe modified the design to a screw-down water resistant type case back, as is the present lot. The present lot is a Ref. 3970E (E for Etanche or water-resistant) which was produced in yellow, white, rose gold, and platinum. Production continued until 2004.

Ref. 3970 is illustrated in Huber, M. & Banbery, A. Patek Philippe, Vol. II, Second Edition, p. 305.