The CamelBak Hands Free Adapter converts all sizes of the CamelBak Better Bottles into a hands-free hydration system. Just attach the PureFlow tube to the bite valve on the bottle and you are set to go!
This did exactly what I needed it to. I put my CamelBak bottle in my bag behind the seat of my kayak and have this adapter clipped to my seat. This way I just grab the bite valve for water rather than look around for the bottle. Only negative - it should come with some sort of sleeve around it because after a few minutes in the sun the water inside the tube heats up. So your first big gulp is very warm until you get to the cold water in the bottle.