Right now on Amazon, you can get this Fitbit Ace 2 Activity Tracker for Kids for Only $39.95 Shipped! (Reg. $70). The swim proof activity tracker for kids 6 plus, Fitbit ace 2 makes family time more fun. It is full of motivating challenges, up to 5 days of battery, sleep tracking and inspiring ways to connect with parents, siblings and friends. There is nothing more meaningful than building healthy habits together and centaury kids is the perfect way to get the whole family moving and making memories.