josodo_hi2288662wrote a review of Osprey Packs Viper 7 Hydration Pack - 400cu in on April 20, 2011
I bought this pack to use for running back and forth to work, small enough so it doesn't weigh me down too much and large enough to bring my lunch. The outside bungee straps rock, I can roll up a change of clothes or bring rain/snow gear. My other pack is an 1800 cu inch behemoth so I figured that this one would be roughly 3 times smaller, the hard plate between the pack and the hydro pack seems to restrict the size. Other than the smaller than expected size I love this pack, I wish I would have gone for a 600cu in though. I plan one using it for several races this year so I can keep my keys, wallet, and other essentials with me.