20-inch Huffy Pro Thunder Boys' Bike, Gray The gun metal gray frame with acid green accents create a cool look; This Pro Thunder single-speed bike (#23307) is ideal for your 5-9 year old child, with a height of 44-56 inches The easy-to-use rear coaster brake is simple to use, just pedal back to stop Complemented by acid green accents, the durable gunmetal gray steel frame is built to last and backed by our limited lifetime frame warranty; Plus, the acid green look adds cool to the wheel rims, 5-spoke chain wheel, pedals and grips The cushioned crossbar pad provides comfort and adds to the overall design; The smoky, translucent chainguard looks cool and the durable steel frame is backed by our limited lifetime warranty Assembly is fast and with only an adjustable wrench, in just a short time it will be ready for your child to ride; Plus, there's a seat quick release for easy height adjustment