Every time I go to fill my k cup filter , it annoys me because it will not stand up on its own. The lid makes it imbalanced and the square piece sticking out on the bottom makes it fall over. This little piece holds the filter cup straight and steady so it can be filled with the beans of your choice.This was printed on my Classic Rostock with Repetier and Slic3r. I used a .35 layer height and honeycomb infill with .3 density. It prints in 30-40 minutes if you goose up the speed, if you want it to look real nice then print at 100% speed. I have printed it at 200% and it still fits etc. There is one glitch in the .stl that keeps the surface from being 100% perfect. I may try to fix it , but as it is it works. I improved the file some. Just checking the fit now.