They have a mouthpiece, a battery, a heating element and a container for the vaping fluid, which is sometimes part of the mouthpiece
You dont need to change your coil-heads, there are no settings to fiddle with, you just fill the pod with e-liquid, adjust the airflow to your liking and youre good to go
But they do know that the substances found in e-cigarette aerosol can stick to surfaces and it is very hard to clean
"A bill to protect the public health by providing the Food and Drug Administration with certain authority to regulate tobacco products
One study examined 9 artificial flavourings alone (like cinnamon, strawberry, and mint) and found that inhalation of these chemicals through tobacco products was linked to blood vessel damage in the heart
Destaillats, we [the Berkeley Lab] had a paper back in 2010 that was, I think, very influential, and in a way, initiated this interest in thirdhand smoke