Boreas Bolinas Pack. The Boreas Bolinas Pack is a marvel for commuters and touring nomads, but don't let its 31 liter capacity fool you into thinking it's too big. In fact, Bolinas has variable suspension technology so the back can be adjusted according to how much stuff is in it. Also, check the hydration port...yep, you can drink on the fly with this guy. Plus it's constructed of 210 denier ripstop pack cloth is treated with silicon to make it that much more resistant to water. And most importantly, this pack is cool looking.