Adult Bicycle Helmet, Black/Silver, L Head Size: With a standard size, suitable for people with head circumference 54-65cm and the head-width below 16cm. You can adjust the size of head circumference with head lock system Cool, More holes, more fresh air,18-Hole Design is not only unique and beautiful design, fashion model, and hole design is very reasonable. It can help increase the speed and keep stay cool. Ultra-light & Comfortable: Rear adjustable head lock system, Washable anti-bacterial pads(Cool comfort pads),and High quality & Durable helmet visor. Special Brim design provides a clear eyesight : The strengthened design of the brim can effectively avoid foreign objects flying into the eyesight of the rider. Besides, it can provide a shade for your eyes. Safety: Use ONE STEP technical material, 90EPS increases impact resistance of composite materials, With CE, CPSCComplies with the U.S. Consumer Product Safety Commission's safety standards for bicycle helmetsCertification.