The Cartier Santos 100 XL Automatic Two-Tone (Reference 2656 / W20072X7 or W200728G) is a prominent, oversized modern homage to the iconic 1904 pilot watch. Introduced originally in 2004 to commemorate the 100th anniversary of the Santos line, this specific version beautifully blends rugged stainless steel with premium 18k yellow gold accents. 

• Case Profile: Nominally 38 mm x 38 mm (or up to 51.1 mm x 41.3 mm including lugs and crown guards). Because of its square architecture, it wears considerably larger on the wrist, mimicking the presence of a 44–45 mm round watch.

• Materials: High-grade brushed and polished stainless steel mid-case paired with a solid 18k yellow gold bezel punctuated by 8 exposed steel screws. 

• Movement: Powered by the robust Cartier Caliber 049 automatic self-winding movement (based on the reliable ETA 2892-A2 platform), which operates at 28,800 vph and provides a 42-hour power reserve. 

• Dial Details: A classic silvered/white opaline canvas displaying oversized painted radial black Roman numerals, an inner railway-style minute track, and luminous oxidized sword hands. It famously utilizes the "watchmaker's four" (IIII instead of IV) and incorporates the hidden Cartier micro-signature tucked inside the 'V' of the 7 o'clock numeral.

• The Crown: Distinctive heptagonal (7-sided) winding crown set with a faceted blue synthetic spinel or sapphire cabochon. 

• Water Resistance: Rated for depths up to 100 meters (10 ATM), which makes it exceptionally robust for a daily dress-sports watch.