All Little Nutty helmets comply with US CPSC Bicycle Helmet Safety Standards for persons age 5 and older. The Little Nutty helmet is size XS, and fits heads 46cm - 52cm or 18" - 20.5". See the Little Nutty Size Chart to determine a good fit. If your head measurement is 52cm/20.5" (maximum size of the Little Nutty XS), we recommend ordering a S-M Street helmet. Each Little Nutty helmet has a built-in Spin Dial Fit System to ensure a snug, comfortable fit..a soft, fabric chin strap for comfort..and the revolutionary Nutcase Magnetic Buckle, which means NO PINCHING!
-Injection-molded ABS shell
-Expanded Polystyrene (EPS) protective inner foam for high impact protection
-2 front intake vents 5 top-mounted exhaust vents, and 2 rear exhaust vents
-Anti-Pinch, Magnetic Buckle for easy, one-handed operation
-Adjustable Spin Dial allows for perfect fit