Garmin vivofit JR.

Amazon.com Price: $37.80$55.65 (as of 02/06/2019 12:12 PST- Details)

1-year battery life – no recharging needed!
24/7 wearability – swim-friendly with 5 ATM water resistance.
Kid tough – easy to put on, the 1-size-fits-most, nonstaining, 1-piece band stretches over your child’s hand and fits comfortably.

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