OLO1933: Features: -Versatile and dependable design, with grooved HDPE out shell, rain trough and accessory slots.-Pin lock adjustment is a sturdy, easy to use 4 point pin lock headband.-Ratchet adjustment headband offers a firmer and more comfortable fit.-All suspension choices feature 3-level height adjustment.-Material: HDPE.-Testing and approvals:.-ANSI Type 1.-Class E.