Those are my anti-tippy wheels. I learned about those from when I owned a Jeep.
Of course that would be my daughter's bike and it was either this bike or the Dora bike since we couldn't find a yellow one. She is still waiting for when I am going to bring home a yellow H2. For the past 2 years she somehow continues to think the white one is temporary. But she is pumped that I am getting a winch on it. Seriously, ask her and she'll tell you that daddy needs a winch for the Hummer.