Four to seven year olds can build riding skills on this lightweight magnesium alloy kids bicycle with 16-in wheels and detachable training wheels that steady the bike while they learn to balance. The adjustable saddle and handlebar let you match the 45 x 21 x 25.5 in frame to a rider height of 41.3-51.2 in so the bike can fit for several years. Dual disc brakes provide strong stopping power, while internal rear brake cable routing keeps the look neat and reduces snag points. A fully enclosed chain guard, anti-skid grips and pedals, and wear-resistant rubber tires support controlled riding up to 145 lbs. The included bell and four reflectors add visibility and fun, and the bike arrives 95 percent pre-assembled to simplify final setup.