Measures steps taken, distance travelled and calories burned. For efficient monitoring of your workouts. LED display clear readouts. Set goals, share progress, and earn badges. As well as log food intake, weight, and more on Fitbit's website or via apps to help make exercise fun. Wirelessly syncs with most Bluetooth 4.0-enabled mobile phones and tablets. Along with most computers, so you can easily review your progress. Apple iPhone and Android apps let you access your data on your mobile device. Water-resistant construction. For durability in a variety of climate conditions. Discreet design enables easy portability. Replaceable battery. Ensures long-lasting use.