Mouse Ears for your slicer.
thingiverse
Mouse Ears add them to your part in your slicer if you're having trouble keeping the corners down and your slicer doesn't already support this feature. Mostly doing this to play with the customizer, so this thing is customizable, try it out. Otherwise there are a bunch of premade ones with differing radii and thicknesses as specified in the names. Let me know if this was helpful to you by posting a make, a screenshot in your slicer of what you added them to might be interesting.
With this file you will be able to print Mouse Ears for your slicer. with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Mouse Ears for your slicer..