Bicycle Helmet Mtb/Road Bike Helmets Cycling Mountain Racing, Men Women Keep Safety, Adult Child Kids, with 22 Vents Adjustable Ultralight Integrally-molded LIGHTWEIGHT & ANTI SHOCK - Silk-light grade color EPS foam structure,effectively reduce the shock pressure. COMFORTABLE - With removable,protective pad liner and sweat chin pad, comfortable to wear and easy to wash. COOL VISOR - The removable visor help to avoid foreign bodies and provide a shade for our eyes BREATHABLE , DRY - 22 flow vents keep your head dry. Head circumference:about 52-61cm, adjustable.