M.U.L.E.® 12 Hydration Pack 100 oz. Fairly used but 100% functional! Please see last picture. Comes with 3L pouch. Redesigning to go the distance with you. Our M.U.L.E.® Hydration Backpacks are already MTB’s best friend, but we've updated the classic go-to pack so you're never left trailing behind. Expect the same trusty M.U.L.E.® with slight body modifications for a smooth ride and fit.