Like All Rolex watches, the Oyster Perpetual Datejust 31 is covered because of the Superlative Chronometer certification redefined by Rolex in 2015. This designation testifies that each watch leaving the model’s workshops has effectively been through a series of exams carried out by Rolex in its own laboratories Based on https://www.watchesworld.com/11-of-the-best-womens-watches/