I got tired of filament pieces and debris fall in the holes around the Z guide rods. There were covers for the z screws, so I made this for the z guide rods. Only caveat is lowering the bed all the way to the bottom, or tall prints, will require removal of these.

I was looking for a cupholder insert for my wife's Ford Bronco. I looked online, and found a few, but they were either expensive, or were ugly, or would ship from overseas. I figured I could design one and print it in TPU and make it exactly how I wanted it.