Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Person Age 5 and older. |One Size Fits Most: 54-61 cm/21.25-24 in |Built-in 5-LED 3-function flashing safety light|Optimal airflow - 15 large vents|Reflective straps and graphics for added visibility|ErgoKnob-2 dial-fit adjustment system|Removable visor and removable/washable padding| Battery size CR2025.
