European Watch Company Logo
Sell or Trade
Audemars Piguet Royal Oak Openworked Perpetual Calendar 18K Yellow Gold FIRST SERIES Ref. 25636BA.0.0344BA.01

Buy This Watch with Apple Pay

Download our iPhone app to buy this watch with Apple Pay.

View in app
Audemars Piguet Royal Oak Openworked Perpetual Calendar 18K Yellow Gold FIRST SERIES Ref. 25636BA.0.0344BA.01

Save this Watch

Download our iPhone app to save this watch, buy with Apple Pay and more.

Save Watch
Audemars Piguet Royal Oak Openworked Perpetual Calendar 18K Yellow Gold FIRST SERIES Ref. 25636BA.0.0344BA.01

Audemars Piguet Royal Oak Openworked Perpetual Calendar 18K Yellow Gold FIRST SERIES (39129)

Audemars Piguet 25636 Royal Oak Openworked Perpetual Calendar, 25636BA.0.0344BA.01, 25636BA00344BA01, 18k yellow gold case with an integrated yellow gold bracelet (fully linked) is in excellent condition and has developed a rich patina, automatic Audemars Piguet perpetual calendar caliber 2120/2802 movement, transparent sapphire dial with yellow gold baton hands, day, date, month, and moonphase, sapphire crystal, display back, C series, diameter: 39mm, thickness: 9mm. Amazing First Series example 25636BA with winding box, service box, and extract from the AP Archive dated March of 1987. This watch was just completely serviced by AP. (39129)


FREE Global Fedex Priority shipping

Sales tax may apply.

More about Royal Oak Openworked Perpetual Calendar 18K Yellow Gold FIRST SERIES

This is an 18K yellow gold Audemars Piguet Royal Oak Openworked Perpetual Calendar 25636BA.0.0344BA.01. It has an integral 18k yellow gold bracelet with a folding deployant clasp, and a scratch resistant sapphire crystal. It has an octagonal winding crown, and there are three correctors in the case bands for the perpetual calendar, including two on the left and one more on the right. It includes an octagonal beveled exhibition sapphire display case back secured with 8 screws, and it's engraved with "AUDEMARS PIGUET SWISS MADE – QUANTIEME PERPETUEL AUTOMATIQUE," and a serial number. The 39mm diameter solid three-body case, bracelet, hooded angled lugs, and flat, polished-edge beveled bezel with 8 hexagonal white gold face screws, are brushed/polished. The dial is rhodium plated with skeletonized components, yellow gold baton hands, and there is a gold perimeter minute scale. The moon phase subsidiary dial at 6 o'clock is created with Physical Vapor Deposited metal on sapphire, and there are three slightly smaller champagne gold rimmed subsidiary dials with black Arabic numerals and letters, and blued indicator hands, including a day register at 9 o'clock, a date dial at 3 o'clock, and a month dial at 12 o'clock. The gold of this watch has a rich patina making it seem more rose than yellow. It has a 40-hour power reserve at full winding, it's water resistant to 20 meters/67 feet, and the 10mm thick case, dial, and movement are all signed. This Audemars Piguet Royal Oak Openworked Perpetual Calendar 25636BA.0.0344BA.01 has a mechanical automatic self-winding Audemars Piguet caliber 2120/2802 (base Audemars Piquet caliber AP2121) perpetual calendar movement. It's rhodium plated with Cotes de Geneve and perlage embellishment, and hand engraving, and it's constructed with 38 jewels, 343 components, a straight-line lever escapement, and an anti-shock device. It includes a Gyromax type monometallic balance that's adjusted to heat, cold, isochronism, and 5 positions a self-compensating flat-balance spring, a mobile balance spring stud holder, and variable inertia blocks on the balance spring. The 21K gold rotor segment is skeletonized and hand engraved, and the mechanism oscillates at a frequency of 21,600 vph (3 Hz). The Audemars Piguet Royal Oak Openworked Perpetual Calendar 25636BA.0.0344BA.01 was first introduced in 1983.

The European Watch Co Process

European Watch Company maintains the highest possible standard in the industry when it comes to the quality of our timepieces. Prior to being listed for sale, every one of our watches are five position tested and meticulously inspected by our on-staff watchmakers. Our goal is to make sure that our watches are in exceptional “like new” condition, both mechanically and cosmetically, so they are ready to wear right when they are delivered to you. To provide further peace of mind, we provide a one year limited warranty on all our timepieces. We have worked very hard over the last 30 years to build up our 5-star reputation. We are confident that we can find the perfect watch for you to cherish and enjoy!

EWC Limited Warranty Logo


I have been dealing with European Watch Company for over ten years, and have purchased several wrist watches, including IWC, Patek Philippe, Rolex, and Jaeger-LeCoultre. They were not only fairly priced but arrived in like-new condition, fully warranted by European Watch Company. This company has an attentive, knowledgeable staff, a large inventory, and is a genuine pleasure to deal with.

P.V. Pawel

Just completed my 7th transaction with EWC and for the 7th time the transaction was smooth, flawless and quick. Joshua is quick to respond to any e-mails and answer any questions. Ashley knows how to complete the necessary paperwork to avoid any delays at Customs as I am located in Canada and all paperwork needs to be completed perfectly which she is an expert at. You only want to deal with the best and the team at EWC is the best. There is a Yiddish word to describe the people at EWC and that word is mensches which translates to people of integrity and honour.

Jeff B.

Winnipeg, Canada

After a lengthy search I located the Patek Philippe I desired at EWC, but the decision to make a high dollar purchase over the internet was a difficult one. Through numerous emails with Justin and looking at reviews of EWC I made the decision to proceed and I am now ECSTATIC. The watch is exactly as described and pictured. It was perfectly packaged and shipped FedEx overnight. My watch collection now includes the watch I have been seeking for over a year.In summary, you can deal with the EWC staff with confidence. They are professional, honest and you will receive a quality watch which will put a smile on your face.

Chuck J.

Phoenix, AZ

I live in San Francisco but the EWC website is the first place I check once I get an impulse for a particular watch. EWC's website is cozy and feels like home. I enjoy the photos, presentation, description and historical notes of each item and really like their next day delivery, so I stay loyal to them. Sometimes I must wait awhile for a watch to become available but can usually find anything I want. Then there are the watches you never knew you wanted until you see them here.

Scott Blalock

San Francisco

Dear EWC, I have just completed my very first purchase with your company: a mint Lange Datograph. Robert was extremely help throughout the process with the item delivered nicely packed to my Hong Kong address within days. The condition of the watch was absolutely mint as described and has exceeded my expectations, even under a loupe! I will be a return customer in no time. Well done!

James C.

Read More Reviews

You May Also Like