18k gold & Stainless Steel, Oyster bracelet (SEL) with flip-lock Oysterclasp and Easylink extension link, 18k tachymeter bezel, champagne dial, automatic Chronometer (Cal. 4131), 12-hour chronograph, screw-down crown, Ref. 126503-0004, warranty dated February 2025, 40mm, 99% Like New in Box with Papers