Reinforcement for the Prusa Research design to fit a 240 micron PVC report cover. Reverse engineered to click in place, may be greatly improved with 250-500 micron sheets. Will stop being knocked out but still can be pulled out on the 240M size, you can only push it so far before the 240Micron sheet deforms. Marked with 240M to distinguish between bottom pieces.
The author hasn't provided the model origin yet.