Four-wheel support from the 12-inch wheels and removable training wheels helps young riders practice balance while staying upright. A hand brake on the handlebar works with the coaster brake so kids can stop by squeezing the lever or pedaling backward. The 34 x 19.5 x 25.5 in overall size gives children ages 3-4 years a bike scaled to their height range of 31.5-41.3 in. An enclosed chain guard helps keep hands and clothing away from moving parts, while a mudguard reduces splashes. Pneumatic tires with layered construction help provide a smoother ride on varied surfaces.