Bought this brand new from Nathan Sports. Used it on 3 or 4 runs and It's a fantastic pack with TONS of storage and super comfy .. but .. it just doesn't fit my oddly shaped body quite right, so letting it go. Please note, you are buying the vest/pack ONLY. I'm not including the hydration bladder in this because 1) I've used the bladder so that just feels weird to resell, and 2) I'm using the bladder on the new pack that I have purchased. That being said, you can buy a Nathan brand or 3rd party brand (like HydraPak) easily in most running/outdoor stores or online. As always, feel free to reach out with any questions. From Nathan Sports Product Description: Run like a professional with this VaporAir 2.0 7 Liter Men's Hydration Pack, voted #1 by Outside Magazine as the "Market’s Best Overall Hydration Vest." Fit is key to avoid chafing while you run so with our Adaptive-Fit™ adjustable sizing system you can have the perfect lightweight, body-mapped pack. Store all of your essentials with multiple pockets and stay hydrated with the 2L bladder with quick release valve. When you are properly equipped, long runs will never be the same. Adaptive-Fit™ adjustable sizing system for tailored fit Breathable, chafe-free materials for maximum comfort Transparent zippered pocket for quick view of essentials Back kangaroo pocket for stashing layers, and more Large main back storage compartment Front pockets fit bottles and flasks up to 22oz Reflect