PC shell for great impact resistance, EPS foam for great buffer action. 10 intake and outlet air vents for comfortable wearing experience, and detachable chin for different sports demand or wearing style. This breathable and lightweight helmet will be a great protector for your kids from unexpected injury during riding, cycling, roller skating and other sports~ Feature:SUPERIOR MATERIAL: Integrated PC shell with great impact resistance which will become spider mesh rather than debris after hit and high density EPS foam with great buffer action to disperse the force impact.COMFORTABLE LINING: Superior absorbent and washable lining for comfortable wearing experience and detachable for cleaning.VENTILATED: 10 intake and exhaust vents create an air circulation system to keep head cool and comfortable.DETACHABLE CHIN: Clip-on chin for all round protection or you can detach it for personal preference or different sports demand.ADJUSTABLE: Rotate the adjustor for proper tightness and suggested head circumference is 20.4-22.0in.SAFE LIGHT: Built-in taillight for safety, 3 lighting mode: constant, flash and breathing.PROTECTIVE: All round protect your face, neck and head from unexpected injury during rollerskating, riding and other sports. Specification:Material: PC & EPSColor: Red & black / Pink / Fluorescent yellow / White / Blue (optional)Head circumference: 52-56cm / 20.4-22.0inAir vent: 10Weight: 387g / 13.6ozPackage weight: 425g / 0.9lb Package List:1 * Helmet