F-400 model features deeper 4" crown protector to extend protection without increasing weight. Incorporates wide-vision (17" x 8") wrap-around windows and screens which provide 40% more protective area than standard size faceshields. Fits easily over required spectacles or respirators. F-500 includes a broader, deeper 7" crown protector to provide an extra margin of protection when harsh working conditions require it. Molded from NORYL, the material used in welding helmets, this model is stronger, more durable and more heat resistant than smaller faceshields made from ordinary material. Features the exclusive Channel Grip System that mounts wide, wrap-around windows and locks them in place in a deep recessed channel to form a perfect seal from dust, dirt and debris. Includes Fibre-Metal classic 3-C, free-floating headgear.