Impact resistance - This bicycle helmet was specially developed for adult BMX riders. The lightweight material consists of robust and hard-wearing PVC and PC-EPS foam, which absorbs the impact and protects the head in the event of an impact. Adequate ventilation: According to the aerodynamic design of the & nbsp; Bicycle helmets have 28 integrated air vents designed to reduce head temperature and resistance. The helmet is combined with the breathable air vents, to create a high / low pressure zone that can evacuate the air.Air front and sides can flow quickly. Can increase speed and stay cool and comfortable. Adjustable size function: The restraint system on the helmet can be swiveled to allow adjustments up and down as well as tension around the head using the user-friendly dial on the back of the helmet. The turning system enables allows you to position the restraint system in the correct position just below the occiput and rock your head perfectly for a calming feeling of comfort. Head size: 56-61 cm. Removable visor & amp; Inner lining: The special design of the visor provides shade while cycling, so that you can enjoy cycling even on hot days and remove the visor blocks when you dont want to wear them and easy to wash. Specialized bicycle helmet: & nbsp; Bicycle helmet, suitable for city, road, electric, trekking, triathlon or mountain bike vehicles, etc. This helmet is specially designed for adult men and women.