The Rolex Oyster Perpetual 31, reference 277200, is a direct descendant of the first waterproof wristwatch introduced in 1926. It has long been the most straightforward offering from Rolex, a simple, yet incredible watch. The reference 277200 was introduced in 2020 and is available with various dial colors. It is cased in 904L-grade Oystersteel and features the caliber 2232 with a Syloxi hairspring and a 55-hour power reserve. The smooth Oyster case and matching Oyster bracelet create a seamless, sporty silhouette.