The Royal Oak 15311SR.OO.D088CR.01 is a limited edition of 50 pieces created in honor of the 80th birthday of the King of Thailand. It features a brown dial with the royal emblem at 12:00 and a diamond-set marker at 9:00. This watch was the first limited edition to be based on the 15300-series.
The in-house caliber 3120 has a total of 280 parts. The rotor, in 22ct gold, is mounted on ceramic ball bearings.