The rear wheels have a car tire valve. The rear wheel tires can be inflated with the Joolz hand pump (possible to order separately) or at a gas station. Remove the valve cupules first, then inflate the tire (like you would do with a bicycle tire). Note: the maximum pressure of the tire is 2 Bar.
Make sure that all the tires are inflated equally (28 P.S.I – 2 Bar). Like tires of a car, the tires should always be at the right pressure to ride comfortably. Right pressure prevent tires to wear and decreases the risk of getting a flat tire.