The Mighty Liquid Pad is made of stainless steel, giving it added strength as well as a high capacity for absorption. The absorption plays well with any type of liquid or oil. The liquid pad is designed at just the right size - thick enough to be safe and secure in position, but also thin enough for two or three drops to give you a refreshing vaping session. You can add more, but 2 to 3 drops are recommended, providing enough flavor without affecting the liquid pad. This liquid pad set contains four durable and absorbent liquid pads.