It measures however it wants. It’s far from a professional measuring device. Sure, it’s nice that it has calibration plates, but what’s the point when it measures the paint on a car I own—one I know hasn’t had any work done—as being hundreds of microns.
Comfortable for the child (soft seat, plenty of space)Safe design (no sharp edges, reliable brakes)Helps with first steps (walking practice, building confidence)Stable while movingNice design