Fox Men's Oasis Hydration Pack 100% Polyamide pockets: 3 slip, 1 zip, 4 exterior, 100 fluid ounce hydration pack, bpa free, phthalate free, pvc free Hydrapak 3 Liter reservoir with detachable drinking tube & slide top large opening for easy filling & cleaning Large main storage compartment to pack essentials for longer rides Channeled padding on back allows for air to circulate & regulate moisture Cinch down straps and flap on outer section designed to securely carry a helmet and lower cinch straps for armor