High density polyethylene construction. Vented feature improves air circulation and reduces heat. Low-profile design with pillowed brow pad & top ribbon pad for comfort. Easy adjustable Durashell double layer crown strap suspensions are replaceable and washable. Vertical height adjustment. Universal accessory slots fit for cap mounted ear muffs and chin straps. Rain through on sides and back of helmet channel moisture away. Meets ANSI Z89.1-2009 standard, Type I, Class C. Chin Strap not included.