Our helmet has excellent protection. It can provide you with the greatest degree of safety when riding outdoors, so that you can enjoy riding.We are also equipped with a professional online service team to solve the problem for you the first time, so that you have no worries ★Product details: Type: Modular Bluetooth Helmet Material: Sturdy and durable ABS shell Buffer layer: High-strength EPS buffer layer Weight: 1600g Size: XS(53~54CM), S(55~56CM), M(57~58CM), L(59~60CM), XL(61~62CM) Safety certification: DOT/ECE Scope of application: Unisex Four Seasons General Recommended Uses For：for motorcycle, cruiser, touring, bicycle and scooter ★Bluetooth parameters: 1. Bluetooth version:V5.0+EDR 3. Transmission distance: 10M 4. Lithium battery:3.7V/500mA 5. Charging time:3 hours 6. Standby time:about 240 hours 7. Continuous working time:about 32 hours ★Package: Motorcycle Helmet*1 Bluetooth headset *1 Sweat-absorbent headgear*1 ★If you are satisfied with my product, I hope you can give us a comment. This is important not only to me, but also to other friends who need this product. ★If you have any questions, please contact us in time, We will solve the problem for you within 24 hours