Adult Bike Helmet With Rear Light For Urban Commuter

US CPSC standards certified, keep your head safe Build-in with detachable rear light, more visibility and safety Adjustable chin strap and rear dial secure system, comfortable and easy fitting Lightweight and comfortable, 9 air vents and detachable inside soft padding Good for urban commuting, bike cycling. Suitable for most adults head circumference from 21.65 to 23.6 inches(NOT for Extra Large). Please measure your circumference above eye brows with a tape measure or string to get your head size and make the right purchase