Non-vented High-Density Polyethylene (HDPE) shell designed with five raised channels running across the top for strength, and an extended back area for extra protectionEPS (Expanded Polystyrene) liner helps absorb impactUnique "3D Adjustment" provides a precise fit using harness depth settings unlike any other hard hat on the US market todayRevolution™ Wheel Ratchet is easy to use and creates a firm comfortable fitIncludes a 4-point cross-over chin strap with quick release buckle that is adjustable for a safe & secure fitChamlon sweatbandMeets ANSI/ISEA Z89.1, Type I requirements, Class E requirementsMeets all Clauses 4.2 of EN 12492Packed ready-to-wear with no installation of the suspension requiredUniversal accessory slots accepts virtually any helmetEVOSpec™ compatible