Really, the main principle is that when drinking water through a straw, the lips must keep a "fish mouth" shape, that is, the upper and lower lips are closed and pursed outward, which naturally involves the inward retraction of facial muscle lines. For example, I used to have a standard pie face, and the sides of my face were fleshy and looked fleshy. However, I have been drinking water from Contigo's straw cup in the United States for the past two years, and I obviously feel that my cheeks are tighter on both sides and the outline is taken in. So I couldn't help grabbing a Contigo cold extraction straw cup recently. It is a new product with high value and can be used instead.