The moisturizing stick is the essence/serum in stick form, which makes it easier to carry everywhere. Unlike liquid form essence and serum, the moisturizing stick doesn't leak.
What does moisturizing stick do?
It provides instant hydration to the skin in a swipe. It can be used even with makeup wearing to avoid flaky skin. Since it's in stick form, it can target precisely the dryness zone and won't make the makeup run everywhere!