At 12 in this is the smallest wheel size in the range, sized for a first-time rider 31.5 in to 41.3 in tall, roughly ages 3 to 4. The pneumatic tires are built in five layers, adding a buffer layer and an outer protective layer over the cord ply and inner tube, so they hold up on gravel and grass. A mudguard blocks spray from reaching the rider. A hand brake and a coaster brake both stop the bike, and the enclosed chain guard keeps fingers off the chain. It arrives 85 percent pre-assembled.