Get ready to feel the power. Vivofit jr. 2, the activity tracker for kids, is swim friendly and kid-tough. It features a 1+ year battery life ; no recharging necessary. Keep the family connected with the free parent-controlled companion app that includes chore and reward management tools for parents and Marvel Avengers app adventures kids can uncover through 60 minutes of daily activity. Garmin vivofit jr 2 tracks steps, sleep and 60 minutes of daily recommended activity. Reminder alerts and task timer keeps kids on top of chores such as homework, practice time and brushing teeth. Offers individual timed activity challenges and toe-to-toe challenges that let kids engage in friendly step competition. Avengers assemble; Every day, kids unfold new adventures in the app as they reach their daily 60-minute activity goals. With you as their sidekick, your little hero goes alongside Captain America and the Avengers as they tackle app adventures in New York City and try to defeat Ultron. This stretchy band comfortably fits a wrist 147 mm in circumference; choose an adjustable band for a larger size. Connectivity Proprietary operating system. Bluetooth 4 connection. USB 2 connection. Display information 11mm Memory-in-pixel (MIP) screen. Battery 140mAh battery capacity. Typical usage time of up to 365 days. Low usage time of up to 365 days. Replaceable battery. Physical specification Size: medium. Watch size H53, W23, D10mm. Strap size L17, W13, T1mm. Strap can be removed and replaced. Weight 17.5g. Features Water resistant. Swimproof. Dust resistant. Pedometer. Distance. Accelerometer. Sleep.