Rugged frame – Made of high-quality steel to deal with learning disabilities; in addition, the durable steel frame has our limited lifetime warranty. Children’s Design 3 – 7 years (83 – 125 cm) for boys and girls – Early riders include a stable training wheel, install it to learn to ride, remove it to learn balance. Quick release seat for height adjustment. Saddle and learn to ride bike holders. Full Chain Protection – Prevent your child from touching the chain, getting hurt or getting dirty. Easy to install – Kids bikes are equipped with 95% assembled body and basic assembly tools, just tire pumps. It usually takes about 20 minutes. Age: 12 inches for 2-5 years old, 14 inches = 3-6 years old, 16 inches = 5-8 years old 18 inches = 7-10.