PRODUCT GRADING ALL GRADES AVAILABLE SEE CRITERIA ABOVE BROWN BOX WHAT IS IN THE BOX Fitbit Charge 2 Heart Rate + Fitness Wristband All Colours Available CHARGER   STRAP *CHARGER AND STRAP NOT INCLUDED IN VARIATION (GRADE C NO STRAP  / NO CHARGER)* PRODUCT DESCRIPTION PurePulse continuous, automatic wrist-based heart rate tracking to better measure calorie burn all day Maximize your workouts using simplified heart rate zones (Fat Burn, Cardio and Peak) See call, text & calendar notifications on the OLED display; Automatically track how long and how well you sleep and wake with a silent vibrating alarm Get a better understanding of your fitness level and see how you can improve over time with a personalized Cardio Fitness Score; Use Connected GPS during run mode to see real-time stats like pace and distance on your wrist Track all-day activity like steps, distance, calories burned, floors climbed and active minutes;Find moments of calm throughout your day with personalized guided breathing sessions based on your heart rate, Like all heart rate tracking technologies, accuracy is affected by physiology, location of device, and different movements. Sync stats wirelessly & automatically to computers and 200+ leading iOS, Android and Windows devices. Operating temperature: 14 degree to 113 degree fahrenheit, Maximum operating altitude: 30,000 feet The minimum and maximum circumference range between 140 - 170 millimeters