That includes a robust chin strap, the ALVEO VENT helmet is a really light-weight helmet for staff at peak. It has air flow holes to permit the air flow to be adjusted as wanted. It’s constructed to be light-weight and its CenterFit adjustment system adjusts the headscarf and retains the helmet centered on the top. The ALVEO VENT is designed for optimum attachment of a headlamp, a protecting protect, and listening to safety.
Petzl – ALVEO VENT, Ventilated Helmet for Rescue Work