Give your skin that hydration boost with the essence HELLO, GOOD STUFF! 48H HYDRATING SERUM STICK. The stick comes in a translucent packaging and is infused with hyaluronic acid as well as cucumber, hydrating your face up to 48 hours. To make it even better, the stick has a cooling effect. For a refreshing feeling, apply the serum directly to your skin and let the product work its magic.