100% Polyester Imported RELIABLE & DURABLE MATERIAL: 20 x 12.7 x 8.6 inches, Capacity: 47.5L; The Mammoth is made of high density durable fabric (100% Polyester) COMFORTABLE & FUNCTIONAL: Heavy duty zippers and utility-style cord pulls, load compression system on both sides, top carry handle, ventilated mesh padded back area & shoulder strap, breathable and comfortable. HYDRATION COMPATIBLE: You will be able to quench your thirst whenever you roam with a hydration bladder pocket featuring a hose port for easy access to H2O (hydration reservoir sold separately) LOTS OF STORAGE SPACE & POCKETS: The Kennebec backpack is the best addition to your adventure. It is designed to provide superior storage capacity and organization without slowing you down. EXTRA FEATURES: two removable internal aluminum stays, padded hip belt to support heavy loads, drawstring closure