For alpine routes or rescue work, this Vertex has a shell that absorbs shock and deflects falling objects. A strong chin strap is rated for falls that generate 50daN. The fit system accommodates a hat and it keeps the helmet nicely centred on your head. CenterFit adjustment system ensures the helmet stays centred and at its most stable angle. 6-point point mesh webbing suspension system is comfortable and adapts to all head shapes. 2 thicknesses of foam bands included for custom fit. Ventilation holes have sliding shutters to adjust airflow and temperature. Side slots let you add or accommodate hearing protection. Clips secure a headlamp with an elastic headband. Inserts work with a Petzl Vizir face shield.