Jig for Dyna Dry Box

It seems that the 4-liter cereal boxes available on Amazon and similar sites all have pushed-in plastic for better grip. Wider spools then have problems spinning freely in the box, so I created this easy jig to widen the handle opening again. Instructions: Heat up your oven to 150 °C. Put the cereal box in for 30–60 seconds. If you notice the plastic getting a bit soft, pull the box out again. Push the jig all the way to the bottom in the handle opening area, facing the long round corner toward the closer end. Put the top cover back on and close it. Let it cool down. During the time the box is in the oven, continuously check if it is soft. If you wait too long, the box can melt very quickly. I printed the jig in ABS, but PETG should also be OK since the box cools down very quickly.