Rolex Daytona "Zenith" 40mm watch with a white dial. (The iconic steel reference: 16520) is one of the most sought-after and valuable chronographs in the world of rare watch collecting. Why is it called the "Zenith Daytona"? The watch gets its famous nickname from Rolex's adoption of the legendary El Primero chronograph movement manufactured by the Swiss company Zenith. Rolex radically and extensively engineered this movement with over 200 modifications (such as lowering the frequency to increase its lifespan and changing the balance wheel), and named it Calibre 4030. Dial (White Dial): The dial comes in a pure chalky white color, and the three sub-dials feature contrasting black outer rings. Sub-dial Layout: The sub-dials are arranged uniquely, distinguishing the Zenith movement from later Rolex movements; the running seconds sub-dial is located at the 9 o'clock position, and the 12-hour counter is at the 6 o'clock position. Crystal and Bezel: Rolex replaced the old acrylic crystal with a scratch-resistant flat sapphire crystal, with a fixed steel bezel engraved with a Tachymeter scale for measuring speed. Bracelet: Equipped with a three-link steel Oyster bracelet with the reliable safety clasp. Movement Type: Automatic Watch Size: 40mm Brand: Rolex Material: Stainless Steel Features: Water Resistant