Kids' helmets are for children between the ages of 3 and 10. It can be just a smaller adult helmet model, resembling a road helmet, or can have a rounder shape like a skate helmet. Usually comes with an adjustable knob that can expand the helmet fitting when the child grows. Those that are for very young children, usually under the age of five, are typically rounder and has an extra rear coverage to protect the child when he/she falls backward.