Watch by Fitbit The ultimate multitasker Built-in Amazon Alexa On-board heart rate (HR) monitor PurePulse measures your heart rate, so you can track your calorie burn, see your resting heart rate trends, and discover your cardio fitness level On-screen coaching feature Provides guidance during every move and routine Over 15 exercise modes GPS and Bluetooth connectivity Battery life up to four days Built-in voice control technology Access apps and store up to 300 songs Compatible with iOS / Android Charging cable included