Why It's CoolThe front is a pack unto itselfa giant bucket pocket stows raingear and bottles, while a watertight zipper opens into a front pouch big enough to house a purifier and your lunch. This makes the Z effectively 300 cubic inches bigger than its stated 3,760-cubic-inch capacity. » Another leakproof zipper gets you into the main compartment from the side; there's no need to embark on a fishing trip from the top. » Back-panel foam is soft and meshy against the skin, firm and supportive, and configured to create a cool chimney channel down the spine. » The full framesheet and center aluminum stay provide mucho stability for loads under 40 pounds.Hmmm . . .The bucket pocket is made of mesh on the sides, inviting poles to poke through. » The lack of bottom compression straps complicates your packing.