What kind of cigarette is an electronic cigarette? made out of what?

Responsibility statement: Smoking is harmful to health. Minors are strictly prohibited from using alcohol allergies,
patients with heart disease, patients with hypertension and respiratory diseases, and women during pregnancy and lactation are strictly prohibited from using it. This product should be stored in a cool, dark environment and out of reach of children.
Please use it reasonably according to your own smoking status. If you feel unwell, use it immediately.