PurePulse® Heart Rate gives continuous, wrist-based heart rate tracking & simplified heart rate zones All-Day Activity: Track steps, distance, calories burned, active minutes, hourly activity & stationary time Reminders to Move: Get friendly Reminders to Move that encourage you to reach an hourly goal of 250 steps Cardio Fitness Level: Get a better understanding of your fitness level and see how you can improve over time with a personalized Cardio Fitness Score Smartphone Notifications: See call, text & calendar alerts on display when your phone is nearby Auto Sleep Tracking & Silent Alarms tracks your sleep quality & wake up peacefully with a silent alarm Sleep Stages shows your time in light, deep and REM stages to better understand your sleep quality SmartTrack™ Automatically recognizes select activities and records them in the exercise section of the Fitbit app Interchangeable Accessories Switch up your look with accessory bands in metal, leather & more Battery life up to 7 days so you can track all day & night without needing a charge. Tap Display Shows your stats, time & notifications on an OLED display, plus customize your clock face Syncs Wirelessly and automatically to computers and 200+ leading iOS, Android and Windows devices