24 Hours- Activity Tracking :Track your steps, distance, calories burned, active minutes, hourly activity and stationary time.Smart Track : Automatically track activities like running, sports and aerobic workouts, then see exercise summaries in the Fitbit app.Auto Sleep Tracking :Automatically track how long and how well you sleep, set a sleep goal and bedtime reminder to form good habits & wake up peacefully with a silent alarm.Water Proof :Track swimming automatically & see your exercise summary in the Fitbit app. Plus, never worry about making a splash—from bubble baths to beach days.Call & Text Notifications :When you get calls and texts, Flex 2 vibrates and the discreet LED display flashes colour-coded lights, so you don’t miss the messages that matter.Reminders to Move :To help you stay active throughout the day, Flex 2 sends Reminders to Move that encourage you to take 250 steps every hour.Better Battery Life :With up to 5-day battery life* in an ultra-slim package, you can track all day and night without needing a charge.