It's self-descriptive. It's here for you to make your own inserts from, altering it however you wish or please.
It was slightly amended due to an implication in a comment that was deleted. Some people said they would struggle with the first measurement because I tried to make it nice and tight. I have since changed a few measurements by 0.5mm to allow for this. as well as better shaping it to take advantage of the entire box.
The author marked this model as their own original creation.