I printed this in PETG for durability, but almost any filament should work fine. No supports are needed, it uses only about 1g of filament, and the total print time is under 13 minutes, making it a fast and inexpensive print. I designed it around my Redragon K556 RGB keyboard to block the Num Lock key, but it should fit most mechanical keyboards with similar layouts. It also works great for blocking other top-row keys if you have a different accidental key press problem during gameplay.