Where and how much did the tank come with it and is it a 18650 or a built in battery
The tank is a dripper, an Aris Pro by Council of Vapor. It is one on the better flavor chasers, IMHO, available. Deep juice well, and it won't leak even when full and on its side because the air inflow is via a hollow tube in the center with ports directed at the coil positions. (It will leak out the drip tip if you turn it upside down, so don't do that, lol.) It normally retails in the $50-70 range, but you can find it on sale sometimes at 25-30. I never saw a used one for sale; folk hang on to those.
The Poldiac is a removable battery mod. The maker, Metal Madness Vapors in Athens, Greece, is presently on hiatus because of the economic crisis. I spoke with Miriam over there and she said their suppliers keep going out of business and they can't get any stainless to make things out of. When they are available, they come with a single size tube, or a set with tubes for all 3 sizes of 18- series batteries. I have 3 tubes; the one in the photo is for an 18650. The only way you can get one just now is used and you have to take whatever the seller has. Hopefully that will change. It's one of the world's best button-type mechs, reasonably priced, and MMV knows they can sell all they can make.