Currently, there are over 100 different versions of the Royal Oak in the collection. It is available in stainless steel, gold, with or without diamonds, with two or three hands, or with a chronograph function, among other options. The 33 and 37-mm watches are well suited for more delicate wrists. The 33-mm version is quartz powered. Diamonds on the bezel, dial, or case increase the value of some models. You have the choice between a classic metal bracelet or an alligator leather strap in black, white, gray, blue, or brown. The case is also available in 18-karat yellow, white, or pink gold.

Highlights of the series are watches with skeletonized dials and movements. The individual movement pieces are so finely finished that they become pieces of art in their own right. You can see the caliber from the front and back in these so-called "openworked" models. The watch has a sapphire glass case back, giving you a look at the automatic movement. Some of these models even have a tourbillon.

Fans of the original Royal Oak should consider reference number 15202ST. Like its predecessor from the 1970s, this watch has a diameter of 39 mm. With a thickness of 8.1 mm, the wristwatch is comfortably thin; it disappears under shirt cuffs without a problem and goes well with a suit and tie. The somewhat larger 41-mm version is only slightly thicker at 9.8 mm. There are few differences between the current model with reference number 15202ST and the original Royal Oak: You are now able to view the movement through the sapphire glass case back, for example. Also, the color of the date disc now matches the dial; the first Royal Oaks had white date discs with black numerals.

The automatic caliber 2121 powers the 39-mm Royal Oak. This movement is incredibly flat at only 3.05 mm thick. It also has a 40-hour power reserve. Its balance wheel frequency is 19,800 alternations per hour (A/h), equal to 2.75 Hz. The movement is comprised of 247 individual components. This Audemars Piguet movement is based on the Jaeger-LeCoultre caliber 920. Without a date function, it's an impressive 2.45 mm thin, making it one of the flattest automatic movements with a central rotor in the world. Patek Philippe and Vacheron Constantin use this movement as well.