This feet fit to the black CTC (dual) printer.
Because CTC changed their laser cut artwork for the case parts several times. This feet fit to the version where the lowest side panel screws are located 25mm above the table where it stands on.
Actually this stl files here are not the feet, this are the adapters to attache normal 30mm rubber feet you can buy in the hardware store next door.
Mine are from Hornbach in Germany and are called door stops cause they where cheaper than rubber feet :-)
To attach each foot to the adapter you need to create M4 threads into the ABS print or if you use PLA I suggest to use 3,5mm woodscrews. Of course woodscrews work on ABS printed parts as well!
The adpaters fit very well even without screwing but to make it stable enough to tilt the whole printer over them when working on the printer bottom I combined them with the bottom screws of the side panel.
Like my upper corners for the CTC this feed also make the whole encasing more stable.
You need to print 2 of each stl to have all 4 feet :-)
If your infill is configured to less than 100% make sure you use at least 3 shells to allow cutting the M4 threads or applying the woodscrews.