Product Details: Brand: ROCKBROS Materials: PC + EPS Removable & Washable Liner: Polyester + Foam Padding Strap: Nylon Buckle: PP/POM Head Circumference: S (48–52 cm) / M (54–58 cm) Weight: S (420 ± 30 g) / M (440 ± 30 g) Dimensions: 31.5 x 17.5 x 21.5 cm 2 IN 1: The chin guard of the ROCKBROS Kids Helmet is easily removable with a button. This allows the helmet to be used not only as a full-face helmet for children and youth but also as a regular bicycle helmet. PERFECT PROTECTION: Our bike helmet features a PC shell + EPS foam + shock-absorbing and sweat-resistant inner liner + integrated design + extended visor, which is safe and reliable and can protect your eyes from the sun. We've added a new style with a detachable visor for you to choose according to your needs. BREATHABLE: With large ventilation openings, this helmet is highly breathable and well-ventilated, ensuring children feel more comfortable during activities. ADJUSTABLE: Featuring a 360° adjustable dial at the back for quick size adjustment. The nylon straps are also easy to adjust. Comes with a removable inner liner, chin strap, and quick-release buckle. The helmet is suitable for children and youth aged 3–15 and is available in two sizes.