The Audemars Piguet Millenary Chronograph Reference 25822ST (specifically variants such as 25822ST.OO.D001CR.01 or 25822ST/O/0002/01 featuring a Roman numeral dial) is a discontinued, late-1990s to 2000s luxury dress chronograph characterized by its signature horizontal oval case.

• Case Dimensions & Material. Crafted from brushed and polished stainless steel, the signature horizontal oval case measures 41 mm wide (approximately 35 mm to 37 mm in height) and 11 mm thick with a 20 mm lug width. 

• Dial & Features. The silvered or white dial features black Roman numeral hour markers, a raised outer tachymeter scale, a magnified date window at 3 o'clock, and three ovoid chronograph subdials at 6, 9, and 12 o'clock. 

• Movement. Powered by the self-winding Audemars Piguet Calibre 2226/2840, which combines a Jaeger-LeCoultre 889 base movement with a Dubois Dépraz chronograph module, beating at 28,800 vph with a 40-to-42-hour power reserve. 

• Crystal & Water Resistance. Protected by a scratch-resistant sapphire crystal with a solid caseback secured by six screws, offering a dress-watch water resistance rating of 20 to 30 meters. 

• Strap & Clasp. Originally paired with a black alligator or calfskin leather strap fitted with a signed stainless steel Audemars Piguet folding deployment clasp.