Protection: This mtb helmets is CPSC standards certified. Material of thickened multi-density EPS foam inside of this adult large helmet impact energy effectively to minimize the risk of harms to head in crash, and extended rear shaped guarantees full protection to cranial part of head. Exploring the rough and rugged mountain trails become more reassured on safety and more enjoyable Optimal Ventilation and Lightweight: To ensure that you benefit from optimal ventilation while save physical strength with this mountain bike helmets mens. 18 air vents is formed on this mens and womens mountain bike helmet,while it weights only 280g, extremely comfortable and very lightweight, hardly feel like youre wearing a mens mountain bike helmet. Experience of mountain adventures are quite fatigue-free and comfortable with cool airflow Adjustment System: Single-Hand dial retention system is easy to adjust and secure the exclusky helmet perfect fit on your head, It is very important for you to get cycling helmet on head properly because potential dangers occurs easily with small or big size helmet. please measure your head circumference correctly before purchase, this mens grey bike helmet size is 22.05-24.01 inches/grey helmet 56-61cm(Adult Sizes) Reinforced Large Sun Visor: Sun visor on cycle helmet is essential to all-mountain biking lovers, This reinforced large sun visor is designed perfectly to match this biking helmet for you - Visor is easy to move upward and secure to offer you broad sights to keep safe, Vents on Visor guarantee airflow pass to keep you cool. More, Large visor with insert-net can better keep discomforts from sun, leafs, other elements away to make you 100% attention on cycling