There are a couple of types of 2 wheel scooters for kids.
The first type is designed for smooth pavement and streets. Not stunts or heavy, impact use. And it's got adjustable handlebars for growing kids.
An example is the Globber Flow 125.
Its 125mm diameter wheels are designed for stability that builds confidence. The larger wheels also help smooth out bumps and travel longer distances more efficiently.
The rubber on these wheels is high-rebound. It means the rubber can quickly absorb chattery impacts and deliver a smooth ride feel.
Globber designed the Flow 125 with adjustable handlebars with a slight curve for better ergonomics. Bar height starts at 82cm then can be adjusted to 87cm, 92cm and 97cm.
The second type of 2 wheel scooter is the kids Pro scooter.
Kids pro scooters are designed for riders who love to ride but they're also more daring; trying new stunts and jumping off kerbs.
These 2 wheel scooters have a few robust features that make them more durable.
Most have non-adjustable, rigid handlebars for strength.
Most also have metal rims on the wheels.
Thicker, reinforced and ribbed decks for extra rigidity when landing tricks.
Extra material around high-stress areas.
Some examples of kids Pro scooters:
The Grit Atom is an entry-level Pro scooter. It can't be pushed as hard as the other kids Pro scooters but it's one of the rare scooters that has adjustable handlebars.
Another option is Proline scooters.
The Proline L1 starts the range. It's a similar kids scooter to the Grit Atom. It has full rigid handlebars instead of adjustable bars.
Next, Proline's L2 scooter has wider handlebars, a wider deck and aluminium rims. So it's a better option for kids about to hit a growth burst.
Note, that the L1 is also available in a Mini version. With a 48cm bar height, the Mini is designed for kids from 106cm to 125cm.