Garmin Vivofit Jr with 1632 battery and green XL band. Needs Battery. Used | eBay
Amazon.com: HQRP 4-Pack Battery Compatible with Garmin Vivofit Vivofit-2 Activity Tracker Fitness Training Computer (2 Batteries fits Training Computer + 2 Batteries fits Heart-Rate Monitor) 010-01225-00 : Electronics
Amazon.com: Garmin vivofit jr. 3, Fitness Tracker for Kids, Includes Interactive App Experience, Swim-Friendly, Up To 1-year Battery Life, Blue Stars : Sports & Outdoors
Garmin Vivofit Battery Replacement Tutorial - Vivofit How To - YouTube