Hydration system fits a 3 liter (100 fl. oz.) bladder, but not included w pack. You’ll need to purchase separately. Rigid spine/handle stabilizes the reservoir, making it easy to slide it into its dedicated compartment; large mouth makes filling/cleaning easy Hydration reservoir pocket has zippered access that extends onto shoulder strap, letting you remove, refill and replace reservoir and drink tube quickly and with minimal fuss Women-specific shorter torso design incorporates padded mesh back panel and mesh shoulder straps for great next-to-body comfort Magnetic attachment on sternum strap keeps the hydration bite valve easily accessible Large zippered main pocket with tool organization sleeves and a mesh pocket is ideal for carrying pumps, bike tools and tubes Front zippered pocket has additional mesh pockets for more organizational options; key clip secures keys Stretch mesh side pockets work great for stashing extra gear or water bottles for quick, easy access Quick-access top zippered pocket is lined with a soft, easy-to-clean heat-embossed fabric that helps keep sunglasses or other fragile items from getting scratched Quickly attach a helmet to the Verve 9 with the LidLock™ helmet clip; bungee on the exterior of the pack allows easy adjustment of the LidLock feature Shove-it pocket can be cinched down to secure bulky items like a jacket Compression straps help stabilize pack and contents; removable webbing waistbelt helps stabilize pack