The Source Vagabond Tactical 2L Hydration Backpack allows you to carry the hydration you need in multiple ways. You can wear it as a backpack, insert it into your pack, or attach it directly onto vests or backpacks using the unique MOLLE-compatible QCA buckle system. Its external fill port has an integral refill handle for easy refill without spillage. Closed-cell insulation helps maintain cool temperatures of your hydration.