I have a Joye ego-t MEGA tank system and need to order 2 CONE shaped attys. They use the cartridges that hold up to 2.5 ml of liquid.
Some suppliers mix their terms a bit.
The original eGo used a cart with a cone shaped cover. A mod for those had a larger cart often called a "mega".
When the eGo-T tank system came out, it used "type A" attys and tanks -- cone shaped attys and 1.2ml tanks. They also came with 650 mAh batteries.
Recently, newer "type B" cylindrical shaped attys came out for 2+ml tanks. You can only use the larger tanks with the cylindrical type B attys, and the smaller tanks with the cone shaped type A attys.
I've seen suppliers advertise an "eGo-T mega" system --- because it ships with 1000mAh batteries.
I ordered my eGo-T from a supplier who called it a "mega" system, with the 1000mAh batteries, and on the order page, you could select type A, type B or LR attys.
With the eGo-T, you're looking at three parts: the battery, the atty, and the tank/mouthpiece. The atty and tank can be replaced with a cartomizer which combines both in a disposable (but refillable) part.
The pricy bit is the batteries. So once you have that, you can mix and match attys/tanks and/or cartos.
In "stock" parts, your choices are the 1.2ml "type A" tank with the cone shaped attys, or the 2ml "type B" tanks with the cylindrical attys. (The type B tanks can be filled with a bit more than 2ml.)
But there are enough mods, cartos, "giantomizers", clearomizers, etc, etc, to make your head spin.
As I'm must getting started, I've stocked up on type B attys and tanks, and a sampling of various cartos to try out.
But lots of mods will fit the eGo-T 1000mAh "mega" batteries.