IKEA UTBJUDA Lunch Box Stack Adapter For Plastic Takeaway Containers

We wanted to stack plastic takeaway containers on top of the IKEA UTBJUDA lunch box, but as the lunch box has a smooth lid and is smaller than most common takeaway containers, I decided to make this adapter.

I also made another version which allows IKEA UTBJUDA lunch boxes to stack together, as can be seen in the last image. Please see my profile for this model.