The outer diameter of most capillary aluminum tubes does not exceed 1 mm, while the inner diameter is smaller, typically 1/2, 1/3, or 1/4 of a diameter less than 1 mm. The color is generally white or silver-white, and a protective coating can be applied to the surface to increase its corrosion resistance. Capillary aluminum tubes have thin walls, are relatively soft, and easy to bend, yet maintain good rigidity and stability.

