<strong>Product description:</strong><p>Fitbit Inspire HR is a friendly heart rate and fitness tracker for every day that helps you build healthy habits. This encouraging companion motivates you to reach your weight and fitness goals and even enjoy the journey with 24/7 heart rate, workout features, calorie burn tracking, goal celebrations, sleep stages and up to 5 days of battery life. Large fits wrist 7.1"" 8.7"" in circumference. Small fits wrist 5.5"" 7.1""</p><p><br></p><strong>Features:</strong><ul><li>Utilize 24/7 heart rate to more accurately track calorie burn, resting heart rate & heart rate zones during workouts</li><li>Track all day activity, including steps, distance, hourly activity, active minutes and calories burned. The Fitbit Inspire band is made of a flexible, durable elastomer material similar to that used in many sport watches, and fastens with a peg and loop</li><li>Automatically track sleep, plus due to the heart rate feature, get more insights into your light, deep & REM sleep stages</li><li>Enjoy up to 5 days of battery for daily progress without constant charging. Varies with use and other factors. Charge time (0 100 percent): 2 hours</li><li>Automatically and conveniently record workouts like walks, swimming & bike rides in a snap with SmartTrack. Stores heart rate data at 1 second intervals during exercise tracking and at 5 second intervals all other times</li><li>Radio transceiver: Bluetooth 4.0. Fitbit Inspire and Inspire HR are water resistant to 50 meters. We do not recommend wearing Inspire or Inspire HR in a hot tub or sauna. Operating temperature: 14 degree to 113 degree Fahrenheit. Maximum operating altitude: 28,000 feet</li></ul>