Kids Youth Offroad Gear Combo Helmet & Goggles DOT Motocross ATV Dirt Bike MX Motorcycle Matte Black M Medium A true youth helmet weighing less than 3 lbs, not an over padded adult helmet Please measure for size. Each manufacturers sizing is different. SIZE CHART (Circumference of the largest part of the child's head, usually just above the eyebrows) in inches: Youth Small: 18 to 19, Youth Medium: 19 to 20, Youth Large: 20 to 21, Youth XL: 21 to 22. Head shapes can affect how a helmet fits. The size chart is meant to be a starting point. Certified to meet the DOT standard (FMVSS 218) Removable and washable liner Helmet and goggles included True youth sized smaller shells, not over padded adult helmets Meets Department of Transportation (DOT FMVSS218) requirements Liner is easily removable &amp; machine washable Soft and comfortable interior Intake vents, channel vents and exhaust vents allow maximum air flow Sculpted shell with side traction plates help keep goggles in place 3 point sun visor for added strength &amp; stylish looks Standard chin strap d-ring closure and strap keeper Helmets are light weight at just under 3lbs, however they are not recommended for children less than 5 years of age Helmet bag included Hard coated clear Lexan lens Removable nose guard 1 3/4&#034; woven strap with anti-slip silicone Replacement lenses available separately Take a head measurement with a cloth tape measure. Wrap the tape measure around the childshead one inch above the eyebrows, directly above the ears and to the widest area at the back of their head. This will give you the circumference, which is the measurement displayed.