Santos 100 41.3 Stainless Steel / Yellow Gold

In Context

At 41.3 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 10.34 mm thick it is about average for a modern wristwatch. The case back is closed, so the movement stays out of sight, and the sapphire crystal will resist everything short of deliberate abuse. 100 m is genuine swimming resistance — more than the shape of this watch suggests it would need.

The movement winds itself from the motion of your wrist. 42 hours of reserve carries it overnight, but not through a weekend in a drawer. At 28,800 vph the seconds hand advances 8 times a second.

W20072X7 stands on its own in this catalogue — no other reference here shares its base number. It pairs a silver matte dial with a yellow gold, stainless steel case.

The 049 No Date is Cartier's ETA 2892-A2 without its calendar, the movement of the 36 mm Ballon Bleu. It powers 32 watches in this library. The 2892 is the thin automatic base the [2892 piece](/blog/the-eta-2892) describes, and Cartier's 049 is that movement finished and regulated by Cartier, at 25.6 mm across with 21 jewels, a 42-hour reserve and a beat of 28,800 vph. Leaving out the date gives the 36 mm Ballon Bleu a clean dial with its Roman numerals unbroken, and a crown with one position fewer. In the library it powers 30 [Ballon Bleu](/brands/cartier/ballon-blue-de-cartier) references at 36.6 mm, in steel, pink gold, yellow gold and two-tone, and 2 Santos 100 references at 41.3 mm. The [049](/calibers/cartier-049) is the same movement with its date, in the 42 mm Ballon Bleu and the Tank Anglaise, and the in-house [1904-PS MC](/calibers/cartier-1904-ps-mc) the movement Cartier built to replace the bought-in bases.

31 other watches in the library run the Cartier 049 No Date.

Cartier

Ballon Bleu de Cartier 36 Automatic Yellow Gold / Silver

W6900356 · 36.6 mm

Cartier

Ballon Bleu de Cartier 36 Automatic Yellow Gold / Diamonds / Bracelet

WJBB0007 · 36.6 mm

Cartier

Ballon Bleu de Cartier 36 Automatic Stainless Steel / Silver

W69017Z4 · 36.6 mm

Cartier

Ballon Bleu de Cartier 36 Automatic Pink Gold / Diamonds / Bracelet

WE9005Z3 · 36.6 mm