Three-position muff can be worn over the head, behind the head, or under the chin. Lightweight durable plastic construction is non-conductive dielectric for tough environments. Universal fit. Headband guards against worker modification of tension. Large earcup openings with soft, foam-filled cushions provide excellent protection and comfort. Includes crown strap for additional support. Pivoting earcup connection maintains seal and alignment. Laboratory tested NRR25.