Protection: This mountain bike helmet is US CPSC standards certified. Material of thickened multi-density EPS foam inside helmet absorb 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 guarantee you benefit from optimal ventilation and save physical strength at same time with this MTB bicycle helmet, 18 air vents is formed on this bicycle helmet while it weights only 320g(0.7lb). 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 cycling helmet perfect fit on your head, It is very important for you to get helmet on head properly because potential dangers occurs easily with small or big size helmet. please measure your head circumference correctly before purchase, This helmet fits head circumferences 22.05-24.01 inches(Adult Sizes) | Reinforced Large Sun Visor: Sun visor on bicycle 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 | High quality service: Exclusky team fully stand behind all Exclusky products, if you are not satisfied with our product for any reason at any time, please contact our Exclusky team timely and we will make it right