Lightness, comfort, and an innovative adjustment system make the Petzl Meteor helmet an essential piece of gear for climbing and mountaineering. . Lightweight and comfortable to wear soft headband conforms perfectly to the shape of your head. Comfortable, breathable foam lining is positioned to stabilize the helmet. Extremely well ventilated particularly appropriate for summer climbing. Magnetic buckle allows for one handed closure of the chinstrap . Chinstrap buckle and headband height easily adjust to provide a perfect fit. Four optimally placed clips hold a headlamp securely in place. Headband adjustment folds into the shell for compact storage and easy packing. Compatible with Petzl VIZION face shield. Size 1 fits 48 56 cm head circumference weighs 7.7 oz.. Size 2 fits 53 61 cm head circumference weighs 7.9 oz.