- Sturdy construction (size 12")
- Excellent brake performance (V-Brake) with child-friendly and soft levers
- Comfortable non-slip pedals
- Comfortable saddle with grip handle for assistance from a companion (pushing, holding, learning balance)
- "Strong" training wheels that are adjustable in height (for learning balance)
- Thick tires (good shock absorption, not tractor-like but with thick treads)
- Aluminum rims
- Normal chain guard (not fake)
- Reflectors (front, rear, and on the wheels)
- Mudguards (front, rear)

Important:
- I believe it is suitable for children with a height of ~100 cm and above, so they can have a good footing. For use with training wheels, it may also be used by children with slightly shorter height.
- Every time the child has fallen (because they will fall), they have not been hit by the bicycle itself.
- The weight is a disadvantage. Not something drastic, just needs to be mentioned. And mainly for the companion, who might have to "carry" it, rather than for the child.