Try improvising one, find any hard paper that could serve as front and back cover.
Then, punch several holes at the sides of the paper as well as the files evenly.
Insert the zip tie on those holes, do not pull it all the way through.

Image Credit: Thaitrick via YouTube
Cut off the excess tails.
you might also use it to secure your electric fans broken wire housing for a quick fix.
*Thanks toThaitrickvia YouTube for all images used here.

4 Clever And Handy Zip Tie Hacks
