This is a divider for the ('industrial') rack boxes: RK4109. According to the internet it should fit in all RK*109 boxes. The original ones go by the name QT109 (I think).
I never had the original inserts so I just made one. It fits nicely without any real gap. You can print is about 0.2mm thicker if you want it to get more "stuck" in the slots but I found them a bit difficult to remove in that case.
Printer Brand:
Prusa
Printer:
I3 MK3S
No
Supports:
No
0.3mm
Infill:
20%
Notes:
I used only 2 bottom & top layers to reduce material costs. They are a bit more bendable in that case, especially with 5% infill. For me the 2 layers / 20% infill is a perfect combination of usage and speed.
It will take about ~15g of plastic according to the Prusa Slicer
The author marked this model as their own original creation. Imported from Thingiverse.