I picked up 4 of the smoktech V2 3.5ml slim DCT tanks (don't like the looks of fat tanks) and 75 regular size boge LR SS cartos at Health Cabin during their Anniversary Sale. The tank bodies are polypropylene rather than polycarbonate (no cracking). I have 3 long barrel drip tips from Siam Mods to extend the length of the cartos to fit the tanks. the joint between carto and drip tip is actually just below the end cap inside the tank. You can pull the drip tip off and fill the tank up without having to move the carto. The tanks were less than $5 each, have chrome caps, don't leak, don't crack, and are easy to refill. Winner all around.