Double Adjustable: Well-attached & long-lasting adjustment dial and skin-friendly adjustable chin strap maxmize the best fit and comfortable wearing. Light Weight: Owing to the well-selected materials and excellent structure, the Lightweight Skateboard Helmet weighs less than 1lb (450g), won't burden your head. As an ideal choice for commuting helmets, this helmet is not only used for cycling, but also for many outdoor activities, such as scooter, roller skate, long board and so on, making outdoor activities more secure and more enjoyable. DOT Safety Certification: Meets or exceeds safety standards.And each batch of helmets is subjected to random quality checks to ensure the highest quality of the products you receive.Size:56-61cm