These are frame spacers for the simplex type beehive. You can use them for broodboxes and honey supers. For the broodboxes, I think the bottom spacers are required since the frames are much longer. For the honey supers you only need the top spacers. Commercial spacers are basically a strip of metal you cut to length, but they lack the capability to position the frames in the middle of the box and distribute the bee space equally between sides.
Each spacer can hold 3 frames, so for the 11 frame simplex, you must cut a spacer (or you could ask me to add a 2 frame spacer). I used 3,0x20mm wood screws to attach the spacers in the boxes. Be aware that the dimensions of your boxes play a role in a good fit!
I don't have a lot of experience with bees yet, but I hope this little project will turn out ok. I hope the bees don't have an adverse reaction to PLA...
I used plain PLA for this project and printed a little hotter than usual (200°C).
These spacers will be outside in the beehives, but will not have to endure the sun's radiation since they are inside the boxes.