Built on a 36 mm round case crafted from Yellow Rolesor — Rolex's combination of Oystersteel and yellow gold — the Datejust 126203-0035 carries a slate grey dial dressed with Roman numeral indices. A scratch-resistant sapphire crystal with a Cyclops lens over the date sits above, while a solid case back and screw-down Twinlock crown contribute to waterproofness rated to 100 metres / 330 feet.
The domed yellow gold bezel frames the dial, and the watch rides on a Yellow Rolesor Jubilee bracelet featuring five-piece links and a folding Oysterclasp with an Easylink 5 mm comfort extension link — a combination that balances practicality with the model's classic character.
Inside runs the Calibre 3235, a perpetual, mechanical self-winding movement from Manufacture Rolex. It features a paramagnetic blue Parachrom hairspring, high-performance Paraflex shock absorbers, bidirectional winding via the Perpetual rotor, and an approximately 70-hour power reserve. The movement carries Superlative Chronometer certification — encompassing both COSC and Rolex's own certification after casing — delivering a precision standard of -2/+2 seconds per day.
