One of the most popular drinkware choices today is the stainless steel insulated tumbler. Whether you’re commuting to work, hiking outdoors, or enjoying coffee at your desk, these tumblers keep your drinks hot or cold for hours. But have you ever wondered — how do they actually work?

The answer lies in two key technologies: double-wall vacuum insulation and 304 stainless steel.

Double-Wall Vacuum: The Secret to Thermal Insulation

The most important feature of a tumbler is its double-wall vacuum structure.

• Two layers of stainless steel – The tumbler has both an inner wall and an outer wall.

• Vacuum in between – Air is removed between the two walls, creating a vacuum layer.

• Why vacuum works – Heat transfer occurs mainly through conduction, convection, and radiation. A vacuum blocks conduction and convection almost completely, leaving only minimal heat loss through radiation.