Grooved HDPE outer shell has rain trough and slots for accessories Available in two replaceable nylon web suspension systems, each with three height adjustments Four-point suspension with pin-lock adjustment is sturdy and easy to use Four-point suspension with ratchet adjustment offers a firmer, more comfortable fit When properly adjusted, ratchet headband keeps cap firmly on head, even when working in awkward, head-down positions Compliance Meet ANSI™ Z89.1-2003 for Type I helmets, Class E.