Make fitness a lifestyle with Fitbit Flex FB401VT Activity Tracker a slim, stylish device that tracks all day activity like steps, distance, calories burned and active minutes. Every day stacks up with LEDs that light up like a scoreboard as you get closer to your goal. Then wear it at night to measure your sleep quality and wake with a silent, vibrating alarm. Day or night, Flex fits comfortably around your wrist, is water resistant, and has a 5 day battery life. It also syncs to computers and 150 leading smartphones, so you can access your stats anywhere and see your progress in charts and graphs.