Impact resistance: Adopting ONE STEP technology materials, EPS plus impact resistant composite materials, ultra-light and lightweight materials; The design of the wind tunnel and air duct effectively reduce wind resistance, effectively reduce the impact of external forces, and protect your head in any unit of directions Fully Breathable: This bicycle helmet is designed with 21 ventilation holes and breathable foam fresh air inlet and warm air outlet, which will bring you cool, dry and comfortable feeling while riding Occasion: The size of the racing helmet is adjustable (57-61cm), and the diameter of the head width is 18cm or less , Suitable for adults, men and women It is very suitable for mountain biking and running in town or in the suburbs, bringing you comfort and protection in outdoor activities Original Design: Our riding helmet has unique design and attractive colors, making you stand out from the crowd Different color changes allow you to choose the right helmet for your style