Audemars Piguet Royal Oak Offshore Tourbillon Chronograph Limited to 50pcs 26421OR. 01 Men’s Watch. The Royal Oak Offshore celebrates its 25th anniversary with two limited editions of Tourbillon Chronographs, in stainless steel or 18-carat rose gold. The redesigned movement has the impact and avant-garde spirit of contemporary architecture. Model: Royal Oak Offshore Tourbillon Chronograph. Case Material: Rose Gold. Box & Papers: Original box, original papers.