Petzl has raised the bar once again with this impressive redesign of their popular Ecrin series. The Vertex's highly adjustable suspension system allows high or low positioning on the head while the unique chinstrap design can be moved forward or back and wider around the ears. The Vertex features a polycarbonate shell designed to withstand significant impact from above or side (meeting EN397 andEN12492 standards) at temperatures down to -30C (-22F). A slot design with clearance over the ears accepts most muff-type ear protection equipment. The comfortable suspension system is adjustable by single thumb wheel and has an integrated chinstrap designed to decrease the risk of helmet loss in case of impact during a fall (breaking strength of more than 50ÊdaN, EN12492 mountaineering helmet standard). The suspension has also been modified to allow the back section of the suspension to pivot which helps minimize distortion. The Vertex Best meets ANSI electrical hazards. Also meets ANSIZ89.1 - 2003-type-I-class-C and CE EN12492.