500D CORDURA Ripstop polyester. Rain defender durable water repellent. Large main compartment with zippered mesh pocket. Dedicated 15-inch laptop sleeve and tablet sleeve. Contour-fit shoulder straps with FastDry sweat-wicking technology. Adjustable, hideaway sternum strap, padded air mesh back panel, adjustable, hideaway padded waist belt. 2 exterior mesh pockets, fleece-lined eyewear compartment. Front zippered organization compartment, Hydration-tube-and-bladder compatible (tube and bladder not included).