I use a CamelBak Rogue for summer 3 gun matches (I go through 70oz and a couple of GatorAides a match)... picked a Blackhawk 100oz Cyclone pack off the prize table at Ft Benning and use it for my car's GHB... like ChaosMagnet don't keep it filled but have bottled water available... like the bite valve on the CamelBak much better than the Blackhawk..