Lixada Bike Helmet Adult Vents Ultralight Adjustable Cycling Bicycle Helmets for Mountain Road Bike Racing Skateboarding Roller Skating Safety Protection Strap adjustment, easy to operate. 25 vents with inner air channels bring cool air in and flush warm air out, well-ventilated. Soft removable, washable, antibacterial pads for best wearing comfort. A quick-release buckle, simple to wear or remove it. Rotary internal regulator at the back . IMPACT RESISTANCE:This Bike helmet uses High-density, durable and tough PVC &amp; PC, EPS foam which is helpful to decrease the impact forces and protect the rider&#039;s head during crash. GOOD HEAD CIRCUMFERENCE ADJUST SYSTERM: The Lixada cycling helmet goes with a standard size,equipped with the easy-use dial system and side straps make this adult helmet adjustable to different head size and suitable for both men and women. VENTILATION SUPER COMFORTABLE: 22 intergrated flow vents help to keep the cyclist cool. Meanwhile it is also helpful to incresase the speed. The inner sponge lining can unpick to wash and it is comfortable and breathable.