This is the rebirth of a true icon. The Longines Ultra-Chron has been inspired by the brand's original Ultra-Chron Diver from 1968. This new watch reflects the design of its legendary predecessor beautifully. Longines' new Ultra-Chron watch is the brand's most accurate watch to date. The timepieces in the line feature a high-frequency movement which guarantees exceptional precision. Core features of the Longines Ultra-Chron collection: Ultra-Chron watches have a high-frequency movement which guarantees they are ultra-precise. Inspired by a diver's watch, the models feature a unidirectional bezel, a screw-in crown and a 300-meter water resistance. Covering the dial is an anti-reflective scratch-resistant sapphire crystal. The movement features a monocrystalline silicon balance spring. Model Specification: L28364529 The case is made of stainless steel and measures 43 mm in diameter.