Once a more a simple 3D printing part. Today, that’ll go into one of the excellent yet affordable (10€-ish, depending on the size of the swappable containers) “EuroPlus Flex” assortment box made by Allit. One of those (yup, stolen right from the manufacturer):

Outer size of that specific product is fixed at 370mm x 295mm x 55mm, and the inside is, aside from the front part that integrates the handle, fully configurable. There are 1×1 boxes in red, 2×1 in yellow and 2×2 in blue. For really large items that still need to be inside a container, there are also 3×2 green and 4×2 gray ones (not shown here), but I tend to just stick them in there without a container. […]