Safety first! The OneK helmets are composed of a Polycarbonate and advance ABS composite injection molded outer shell combined with an EPS liner. The EPS liner is the main part for impact absorption in a helmet. OneK uses only EPS of a high quality with a density making the helmet perfect for impact absorption. VG01 approved.ComfortThe OneK helmet provides you with a very high level of ventilation featuring two front ventilations, two side, one back and two center stripe ventilations. The helmet has comfort padded harness with synthetic suede lining, hook and loop adjustment and a fast-tex buckle.The OneK helmets are available in 3 shell sizes. By using the OneK liner which is available from XS to XL you can achieve the perfect fit. The OneK liner is made of a washable quick-dry fabric, it is moisture wicking and anti-microbial. Attention! Liner is sold separately and is not included with the helmet.DesignOneK Helmets boast the perfect synergy between advanced technology and aesthetica