Style meets function in the Citizen Nighthawk with a sporty appeal. Designed with a granite ion-plated stainless steel case and bracelet with a charcoal gray dial with red accents, the advanced features include a 1/5 second chronograph that measures up to 60 minutes, 12/24 hour time, and a tachymeter that measures speed based on time traveled over a distance. This must-have men's watch features a safety foldover clasp with push button, and water resistance to 200 meters. Made with our proprietary Eco-Drive technology that's sustainably powered by any light and never needs a battery, this versatile men's watch becomes your weekday to weekend wardrobe staple. Caliber number B620.