Helmet information:Name: Motorcycle Retro 3/4 Half Helmet Unisex Bluetooth Motorbike Open Face Helmet Moped Scooter Helmet for Men & Women with Double Visor Built-in Earphone Microphone DOT/ECE ApprovedBluetooth headset: Built-in battery 3000 Mah, battery life of 88 hours, standby time of 30 dayrs, waterproof, noise reduction, stereo sound, good sound quality, high-definition microphone, automatic answering of calls, fast charging, Applicable head circumference: M:57-58cm(22.4-22.8 inches) L:59-60cm( 23.2-23.6 inches),XL:61-62cm(24-24.4 inches),XXL:63-64cm(24.8-25.2inches)ABS helmet body, high impact resistance, heat resistance, low temperature resistanceHigh-density EPS buffer layer and comfortable lining, shock absorption and impact resistance.US: DOT certification, EU: ECE 22.05 certification standardAerodynamic ventilation system,Comfortable inner lining, removable liningDouble lens, sun-shading and sun-proof outer lens, anti-glare inner lens.The outer lens defaults to a transparent lens, if you need a black lens, please contact us by email!Applicable people: adults, teenagers, boys, girls,men,womenApplicable season: all seasonsPACKING LIST:1 *Motorcycle Bluetooth Flip up Modular Full Face Helmet1* USB Cable1*User ManualMEASURING TIPS:Special Note: For an accurate head measurement, wrap a soft (tailor) measuring tape horizontally around your head about 1" above your eyebrows.