Lightweight Design: The fast helmet is made from high strength ABS plastic materials, reducing the burden of wearing and enhancing comfort. Upgraded Rail System: This helmet is equipped with an adjustable rail system for various accessories such as goggles and cameras, enhancing flexibility and expandability of use.Built in Headset Slots: The outdoor helmet features a dedicated earphone slots design for easy installation of headsets or other ear accessories. Enhanced Protection: The helmet with with earphone slots provides great impact protection to effectively reduce the risk of injuries during activities.Stylish Design: With its classic pure color design, this helmet with headset slots has a simple yet elegant appearance, easy to match with other equipment. Specification: Material: ABS Plastic Size Chart: 22cmx16cm/8.66inchx6.30inch Package Includes: 1 Fast Helmet Note: Please allow slightly errors due to manual measurement and different monitors.