Bicycle integrated riding helmetProduct NameIntegrated bicycle helmet [Model] H 068, adult helmet, both men and women. [Size] L one size, head circumference 54 62cm, head width 17cm, head length 21. 5cm, with adjuster knob, can adjust the head circumference size. [Materials] The US imports EPS foam + imported PC sheet is integrally formed, built in high grade lining, imported nylon webbing and PP material regulator.