Audemars Piguet’s reference 4100 is to the 5402 what Patek Philippe’s reference 3800 is to the 3700: a more wearable interpretation of an icon.

During the 1970s, alongside production of the legendary Royal Oak, Audemars Piguet introduced a reduced-size version of the design. Measuring 36 mm, the reference 4100 sacrifices nothing in character or presence. It delivers the same bold, architectural design language as its larger counterpart; robust yet refined, sporty yet elegant. But this all in a more versatile size.

This example features a grey “petite tapisserie” dial with an applied logo and 18k yellow-gold applied hour markers. The crisp white printing offers strong contrast against the dial, enhancing legibility while preserving the watch’s understated sophistication. It also retains the vintage Audemars Piguet signature in what many consider the brand’s most attractive font, with all letters capitalized. Beautiful patina and subtle discoloration can be seen around the applied baton markers with tritium lume, adding warmth and character to the dial. The 18k yellow-gold case and signature octagonal bezel remain in excellent condition, with sharp definition throughout. The bracelet also remains remarkably strong, and the clasp proudly displays the AP signature in crisp detail.

Powered by the ultra-thin calibre 2123, the case measures just 8 mm thick. Combined with the integrated bracelet, this gives the watch an exceptionally elegant profile and ensures a refined, comfortable fit on the wrist.

This reference was introduced in 1977 and this exact example being from 1978, as confirmed by the extract. It has a remarkably low number on the caseback: 2X.