High tech head cradle provides the best stability and has unique thumb wheel adjustments positioned on both sides. One allows you instant size adjustment... the other lets you dial in the tension at the nape of the neck - key to maintaining the forward attitude of the helmet and its position in the event of a fall. The ECRIN ROC sets the standard for durability and protection for rock climbers, big wall climbers, alpinists and mountain rescue personnel who wish maximum protection. Discreet headlamp strap retainers and excellent ventilation ports - which can be "plugged" with the accessory BOUCHON (not shown).