16mm outer diameter X 12mm inner diameter
Available is a variety of diameters by 1 meter in length.
Sizes are listed with outer diameter first, then the inner diameter. For example, 3mm X 2mm would measure 3mm outer diameter with an inner diameter of 2 mm. From this we know that it will have a wall thickness of .5mm . (outer diameter - inner diameter / number of walls)
Sold by the stick, each stick is 1 meter (39.37") long.