Happyjoy Cycle Bike Helmet Vented Design Lightweight 58 - 61cm Head Circumference with Detachable Visor- Sliver Material: PC shell(more durable than PVC), EPS inner shell-Shock absorbing EPS inner liner for added protection Fits most adults (58 - 61cm/ 22.8 - 24 inches Head Circumference), Dial-fit retention system can adjust the size of head circumference. Vented design - 16 air vents for maximum comfort Lightweight design, weighs only 240g. Come with snap-on visor Meets CE and EN1078 Certification