This full face helmet is constructed from hard polycarbonate shell with shock-absorption EPS foam to provide maximum protection for your kids. It Features 13 air vents, vented mouth protection, sun visor, adjustable dial, removable liner and other advantages that bring much fun for your kids. The helmet is also detachable to use as a half-face helmet, very convenient to use. Features : 2-in-1 Helmet : Detachable design makes it easy to convert between full face and half face helmet with a push button in both side of the helmet. Integrally-molded : Hard polycarbonate shell and shock-absorption EPS foam provide impact protection. Visor provides increased shade for your kid 's eyes. Good Ventilation : 13 flow vents promote hot and cold air transfer to keep your child cool; vented mouth protector for enhanced breathability. Adjustable Size : Easy-to-adjust dial provides a customized fit for different head sizes. 2 sets of liner pads (with 1 set assembled ) are provided for easy replacement and cleaning : 12mm thick liner is used for 52 - 56cm head circumference, and 8mm liner for 54 - 58cm head circumference. Great Protective Gear : Perfect for your child while cycling, skateboarding, roller skating, riding a scooter, longboard, or doing more sports. Specifications : Material : PC + EPS Color : Black&Green / Blue&White / Red&White / Blue&Purple / Grey (optional ) Inside Size : 21.5 * 17.5cm / 8.5 * 6.9in Head Circumference : 52 - 56cm / 20.5 - 22.0in (use 12mm liner ); 54 - 58cm / 21.2 - 22.8in (use 8mm liner ) Weight : Approx. 450g / 1lb Package List : 1 * Helmet