This full face helmet is constructed from hard polycarbonate shell with shock-absorption EPS foam to provide maximum conservation for your kids. It features 13 air vents, vented mouth conservation, 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: Detachable design, easy to convert between full face and half face. Strong PC shell and EPS foam absorb shock and impact. 13 flow vents keep your child cool; Vented mouth conservation. Visor provides increased shade for your kid's eyes. Adjustable dial makes the helmet fit head sizes: 52 - 56cm (use 12mm liner), or 54 - 58cm (use 8mm liner). Removable, washable liner keeps helmet clean, fresh, and odor free. Protect your child while Cycle, skateboarding, roller skating. Note: We provide two sets of liners: 12mm thick liner is designed for 52 - 56cm head circumference, 8mm pads for 54 - 58cm head circumference. Specifications: Material: PC + EPS Color: Blue / Red / Yellow / Rose Red / Light Blue / Green / Grey / Discoloration/Bright yellow/Purple(optional) Head Circumference: 52 - 56cm / 20.5 - 22.0in (use 12mm liner); 54 - 58cm / 21.2 - 22.8in (use 8mm liner) Weight: Approx. 420g / 14.8oz Package List: 1 * Bike Helmet