Camelbak BFM 100oz Hydration System is the ruck sack you need when you're on a long mission and always on the move. This Camelbak hydration pack will support your extended operation. The Camelbak BFM Hydration Pack is Camelbak's largest system, with a versatile load configuration design that can carry it all comfortably. The Camelback Water Pack BFM lets you pack out 2600 cu. in. (4.2 L) of gear and up to two 3-liter reservoirs of water internally.