Zip ties get used for lots of things, including as a part of the termination of flexible ductwork. In this capacity, they hold the outer insulating layer in place.

There are also other methods by which to do this, but some tradespeople prefer it.

Anyway, round ducts are girthy things to encircle. A circle with circumference of 48 inches has a diameter of just over 15 inches, which is not big at all in ductwork world.

(But such zip ties aren't shaped like the $75 wanktastic dumb shit that the article is about. They're just long.)