Fitbit CHARGE HR Activity & Fitness Tracker with Heart Rate, 7 Day Battery & Sleep Tracking - BLACK

Let your heart be your guide with Charge HR
Monitor heart rate automatically and continuously right on your wrist
Take control of your goals using Charge HR to record workouts and track all-day activity
With a comfortable fit and Caller ID, Charge HR lets you stay connected in style
Use Exercise Mode to easily record workouts, see real-time exercise stats and have summaries automatically appear on your Fitbit dashboard
Get a better picture of your overall health by using Charge HR to automatically track how long and how well you sleep
Small band is 5.4"- 6.2"
Large band is 6.2"- 7.6"