The Basics

The Royal Oak Extra-Thin 15205BA.OO.1240BA.01 was introduced in 2015 as a limited edition of 50 pieces for the 50th anniversary of Singapore retailer The Hour Glass. It was the first Royal Oak to [again] use yellow gold – a material notably absent in many collections for a number of years, with pink & rose reigning supreme.

Brand: Audemars Piguet
Family: Royal Oak
Reference: 15205BA.OO.1240BA.01
Name: Royal Oak Extra-Thin The Hour Glass
Produced: 2015
Limited: Yes, 50 units

Below is a detailed look at Audemars Piguet’s model 15205BA.OO.1240BA.01 from Royal Oak watch family, including the price, case details and movement features.

Audemars Piguet Royal Oak 15205BA.OO.1240BA.01

- Advertisement -

The Details

Audemars Piguet’s Royal Oak Extra-Thin The Hour Glass (15205BA.OO.1240BA.01) was originally released in 2015. This watch features a automatic movement beating at a frequency of 21600 bph ( 3 Hz) to provide a 40-hour power reserve when fully wound.

The Case

The yellow gold case measures 39mm in diameter and roughly 8.1mm thick. The N/A case is paired with a green color dial with stick-shaped hands, and a stick / dot hour markers and minute track, covered by a sapphire glass. Audemars Piguet’s Royal Oak model 15205BA.OO.1240BA.01 is water resistant up to 50 meters (164 ft). A display caseback is over the back of the watch case.

Material: Yellow gold
Glass: Sapphire
Back: Display
Shape: N/A
Diameter: 39mm
Height: 8.1mm
Lug Width: N/Amm
W/R: 50

Case Diameter

Case Thickness

Lug Width

Water Resistance

The Movement

The Royal Oak 15205BA.OO.1240BA.01 movement is a powered by caliber AP 2121 made by Audemars Piguet. The 36-jewel automatic movement is 28.4mm in diameter. Its balance wheel oscillates at 21,600 semi-oscillations per hour or 3 Hz. This movement offers a 40-hour power reserve.

Type: Automatic
Brand: Audemars Piguet
Caliber: AP 2121
Base: N/A
Display: Analog
Diameter: 28.4mm
Jewels: 36
Reserve: 40 hours
Frequency: 21600 bph
Time: Hours, Minutes

The Price

How much does the Audemars Piguet’s Royal Oak 15205BA.OO.1240BA.01 cost? This watch was introduced in 2015 and has been in Audemars Piguet’s collection for around . This watch is a limited edition with just 50 pieces released. As with most luxury watches, the price of depends on the availability and demand.

CURRENT PRICE: $56,900 .

For more information, visit Audemars Piguet online.


  • Brand: Audemars Piguet
  • Model: Royal Oak Extra-Thin The Hour Glass
  • Reference Number: 15205BA.OO.1240BA.01
  • Limited: Yes, 50 units

Case & Dial:

  • Material: Yellow gold
  • Glass: Sapphire
  • Back: Display
  • Diameter: 39
  • Thickness: 8.1
  • Lug Width: N/A
  • Dial Color: Green
  • Indexes: Stick / Dot and Stick-shaped hands
  • Water Resistance: 50 meters


  • Winding: Automatic
  • Brand: Audemars Piguet
  • Caliber: AP 2121
  • Display: Analog
  • Diameter: 28.4mm
  • Jewels: 36
  • Power Reserve: 40 hours
  • Frequency: 21600 bph
  • Functions: Hours, Minutes

About Audemars Piguet

Audemars Piguet logo

Jules Louis Audemars and Edward Auguste Piguet met in 1874. The two watchmakers began working together, founding Audemars, Piguet et Cie, one year later in 1875. To this day, members of the two families sit on the board of directors for the company. This makes Audemars Piguet one of the oldest family-run manufactures.

Audemars Piguet Watches

Discover new luxury watches and watch brands for men and women from our database of over 20,000 watches across more than 100 different brands.


Please enter your comment!
Please enter your name here