Title says it all. A cart that has a small air channel on the inside. The straw mod revolutionized my vaping experience. Topping off is easier, wicking is far better, no liquid gets popped out of the cart (and into your mouth) by expanding air pockets, and the carts drag completely dry.
I don't see any model numbers listed in these posts. Are you looking for a round 510 cart, approx the same length, with double the juice capacity and a built-in vent tube? What other models?
similar to the 401 carts, kinda. but i have one kind of 401 cart that really "sucks" had just puts juice in the mouth piece, and i have another that works pretty much like a charm. but they still dont have an actual air release where the filler is. so the chambers would still have to be where the filler is..... ugh, i dont think i made sense...I'd say that the easiest way of doing it would be to have a mouthpiece with an internal chamber for the cart, to suspend the chamber you would create channels that would act as the straw. whether to perforate the bottom of the internal chamber to create some airflow back through the filler (for flavour) or to leave it solid to create maximum suction of liquid up through the wick would probably have to be tested.
Apologies if this isn't what others had in mind, it is however what I'd like to see. And particularly for the 901.