All (new) Sage rods come with a standard tube! The one with an attached reel pouch is purchased separately (they sell them in different lengths, so make sure you know is your buying one for a 4 piece, 3 piece and what length for the specific rod)! If you have one for a another rod already, if it fits, you're golden, unless you are bringing a quiver with you then you need one for each rod... In that case, as I do (as many others), I have a double rod tube to bring 2 loaded rods with me, ready to go!!
Cheers,
P
P.S. Most fly shops and other fishing retailers will have them...