Features1ADJUSTABLE: Turn the knob at the back for proper fit, the suggested head circumference is 22.4-24.4in. 2BREATHABLE: 22 air vents increase air circulation and reduce sweating to keep your head comfortable during Cycle. 3PROTECTIVE \u0026 SAFE: Impact resistant PC is not easy to crack and high density EPS foam is buffered, which surely improve safe performance.SpecificationImpact resistant PCwith high density EPS foam to protect your head from unexpected injury; detachable visor is UV protective to block out harmful sunlight, and the back light provide safety lighting for night riding. A nice bike helmet for your riding trip! Features:ADJUSTABLE: Turn the knob at the back for proper fit, the suggested head circumference is 22.4-24.4in. BREATHABLE: 22 air vents increase air circulation and reduce sweating to keep your head comfortable during Cycle. PROTECTIVE & SAFE: Impact resistant PC is not easy to crack and high density EPS foam is buffered, which surely improve safe performance. UV PROTECTIVE: Detachable visor reduce the harm of strong sunlight while protect your face and eyes from wind, sand and dust. SAFETY LIGHT: Built-in a back light with 3 modes for warning and lighting in darkriding,includes always on mode,fast flashing mode and slow flashing mode. COMFORTABLE: Take down the absorbent lining and soft chin pad for cleaning and a quick release buckle for easy take off. Specification:Color: Green & black / Yellow & black / Blue & black / Black & white / Red & grey / Red & white / White & grey / Blue & white / Silver & grey / Silver & red / Rose red & black (optional) Material: PC + EPS Air vents: 22 Head circumference: 57-62cm / 22.4-24.4in Battery: 1* 3.0V 120 mAh CR1632 battery Weight: 281g / 9.9oz Package weight: 349g / 13oz Package List:1* Bike Helmet 1* Detachable Visor NOTE:Item color displayed in photos may be showing slightly different on your computer monitor since monitors. Thank for your understanding.Package List1* Bike Helmet 1* Detachable Visor NOTE:Item color displayed in photos may be showing slightly different on your computer monitor since monitors. Thank for your understanding.