holds the shavings from sharpening
just glue your own (caseless) sharpener into the middle (use a pencil to line it up)
I recommend printing the main body out of PLA or other hard plastic, then printing the lid out of TPU for easier fit, but PLA will also work if your printers tolerances are tight enough, I tried both on my ender 3 pro and both worked. if not just scale up the lid ever so slightly.
the lid does just friction fit to easily slide on and off for emptying but does stay on well enough