The Condor Outdoor HCB2 Hydration pack is an excellent stand-alone backpack as well as add-on MOLLE pack. With shoulder and chest straps it can be worn as-is for hikes and other outdoor activities. It's MOLLE straps and webbing allow the shoulder straps to be removed and the pack to be directly weaved into the MOLLE on a plate carrier or other MOLLE compatible vests.
Two zipper compartments
Removable shoulder & sternum straps
MOLLE webbing and straps for attaching to vests/carriers