The new Polar M430 is a triple threat, integrating state-of-the-art running metrics, advanced GPS and the freedom of optical heart rate technology - the ultimate training partner for runners who demand more. This is a great all-around sport watch. Syncs with Polar Flow (free) for easy logging of your training. Can be paired with Polar H10 Chest Strap for ekg-accurate measurement. Rechargeable via USB cable. For more details specs see polar website here: https://www.polar.com/us-en/products/sport/M430-gps-running-watch