Gregory Z 25

Backcountry.com says:
When you're out all day, you want to be prepared without being weighed down. The Gregory Z25 Backpack's low weight and sleek design belies its substantial carrying capacity; you can stuff 35 pounds worth of gear and snacks in it without worries. It's a breeze (literally) in warm weather, thanks to the updated CrossFlo suspension system that places ventilated EVA foam at the hip belt and shoulder straps to increase airflow. The interior sleeve with hydration port and side mesh bottle pockets store plenty of water to keep you lubricated on long hikes in the mountains, and hideaway gear loops will carry an ice axe or trekking poles when the day's objective is more technical.