The Citizen CZ Smart Hybrid Extreme 44mm smartwatch blends iconic design and smart technology. It comes equipped with a heart rate sensor, sleep tracking functionality, and a variety of activity tracking modes to help you hit your health and fitness goals. It connects easily via Bluetooth to your smartphone and has a generous 18-day battery life. | Citizen CZ Smart Hybrid Extreme 44mm GPS Smartwatch with Heart Rate Monitor- Medium / Large - Blue