Basecamp Bike Helmet, Cycling Helmet with CPSC Safety Certified/LED Safety Light/Removable Visor/Flow Vents-Safety and Comfortable for Adult Men/Women/Youth Mountain&Road SPECIAL MATERIALS IMPACT RESISTANCE: The Basecamp bike helmet uses High-density, durable and tough PVC & PC, EPS foam which is helpful to decrease the impact forces and pprotect the rider's head during crash. EXCELLENT TAILLIGHT WITH BIG LIGHT AND BACK UP BATTERY : LED Safety light, with 3 lighting modes - steady, slow flashing and fast flashing will help people behind you clearly recognized your direction.And a back battery is included as for extra bonus. GOOD HEAD CIRCUMFERENCE ADJUST SYSTERM: The Basecamp cycling helmet goes with a standard size,equipped with the easy-use dial system and side straps make this adult helmet adjustable to different head size. Besides, there are two holes for attaching to adjust the size suitable for small or larger head forms.Weight: 0.35 KG/0.77Lbs Head Size: 53-58 CM/20.86 -22.83 VENTILATION SUPER COMFORTABLE: 22 intergrated flow vents help to keep the cyclist cool. Meanwhile it is also helpful to incresase the speed. The inner sponge lining can unpick to wash and it is comfortable and breathable. DETACHABLE BRIM STYLISH DESIGN: The special design of visor provides shade when biking, so that you can enjoy cycling even in hot days, and you can take off the visor blocks when you don't want it. With  Lightweight tough and durable PVC &amp; PC outer shell and EPS foam liner, effectviely avoid the damage caused by the huge impact on the head.