REI Flash 18 Pack

Lightly padded stretch-mesh shoulder straps enhance comfort
Back panel is also lightly padded
Hipbelt and sternum strap can be detached
Sternum-strap buckle doubles as a safety whistle
Hydration-compatible design includes a hose exit port and an internal sleeve for a reservoir (reservoir not included)
Drawcord closure fully covers the top opening when cinched tight
Pack has a zip pocket inside and 2 daisy chains outside