U.S.G.I. Brand new 2 Quart Canteen - O.D. NIB. In this case, NIB means Brand new in a huge box, not individual boxes so your canteen will not come in the original box unless you are purchasing a whole case of 40 Canteens.

These canteens come with the Chemical Mask adapter capMIL-C-51278D NSN #: 8465-00-930-2077 (Olive Drab) -- Enables user to drink from a canteen while wearing a gask mask Fits standard 1 and 2 quart military and NATO standard 28mm military canteens Adapter has a pressure valve fitting gasket, cover and a coupling with a self-sealing valve The cap alone sells for $5.99 to $18.99 from my Competition.

I am not responsible if your Mask does not come with the tube, and "no", I do not sell tubes that attach to a pre manufactured mask that you own.