Tanks

This is an example of a tank – they come in all shapes and sizes, though.  A 'tank' sounds 'big' but it isn't.  All it is, is a cartridge that is empty, but with an important difference. Where an empty cartridge (which you re-fill with liquid), or a used cartomiser contains a kind of gauze that you soak in liquid, the tank is a (usually) transparent 'cartridge' that is completely empty.  You fill it with liquid and then plug it into an atomiser.  

Note though that a tank usually has to be used with a special atomiser that is different from a normal atomiser - the tank atomiser punctures a hole in the tank itself, to let the liquid through, so it is a different design to an atomiser that you use with a cartridge.

Tanks are OK, once you get used to them, but many people (particularly ‘newbies’) find them messy and/or hard to re-fill.  We prefer a simple battery/cartomiser ‘plug-and-play’ option.

Recommendation:   Avoid tanks, at least to start with.  You might find, later on, that you want to give them a try...