... air vents,good ventilation ,204g 4,factory direct price Bicycles Helmets (39 air vents,in-mold technique) Name 39 Air Vents ... vents 21size L(58-63cm)Sale Status Hot sell, off the shelf Specifications and Advantages TUV,CE certification;39 air vents ... , good ventilateBuilt-in in-mold technique , the cover is very goodfasten elastic could adjust, sweat absorption Packing ...