Divider for RK4109 Rack Boxes

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.