Isenretail Climbing Helmets Limit Outdoor Climbing Caving Rescue Helmet Bike Camping Helmet (Green) 54-62cm adjustable dimension around the head. Width about 18cm (Free Size) 12 vents, easy to heating rediation Weight: 290 g, very light. A color screen integrated PC shell material injection molding high-temperature thermoforming closed breathable absorbent excellent memories velvet lining