The HydaPak Reversible Reservoir with Shape Shift Baffle fits in low profile packs better than most bladders. That's because its Shape Shift Baffle the blue vertical line in the center of the reservoir connects both sides together in order to give the reservoir a slimmer profile. This slim profile allows you fill your pack up with more snacks, gear, and toys for the outdoors. Its reversible design and wide slider opening make it easy to clean. The Plug N Play connector tube is easy to take off and on, and the bite valve lets you drink on the go.