Netti My Bike
Balance bikes have been made out of both metal and wood. It can be a normal bicycle with pedals and related parts removed, or it can be purpose-built (especially for very small children, for whom normal bicycles are generally not available). It can have no brake, or it can have one or two hand-activated rim brakes.
To function properly, a balance bicycle must be small enough that the rider can walk the bicycle while sitting comfortably in the saddle, putting both feet flat on the ground. The rider first walks the bicycle while standing over the saddle, then while sitting in the saddle. Eventually, the rider feels comfortable enough to run and "scoot" while riding the bicycle, then to lift both feet off the ground and cruise while balancing on the two wheels.