Why It's CoolThe framesheet is classic GoLite technologymade of corrugated polystyrene and ultrathin aluminum dowels, it provides support and structure yet adds only six ounces to the two-pound-seven-ounce pack. (Fanatics needn't fret; it's removable.) » The lumbar pad is the unsung herothe ribbed design keeps the pack from slipping and breathes well. » Wide-open mesh against the shoulder blades made this one of the coolest packs we've tested. » Pack-body fabrics are gossamer thin but waterproofand reinforced at the bottom and pockets. » There's an inner hydration sleeve and two side mesh pockets within grab-on-the-go reach. » Neat detailing: garages for the front-pocket zipper pulls; a gusseted mesh hem at the bottom of the pockets keeps small items from spilling out.Hmmm . . .The woefully small lid pocket wastes space.