Size do matter when tamping coffee. This is a 58mm coffee tamper. It's a bit longer than expected though and from a certain angle it has a strange look to it...
After removing from the print bed it needs a bit of sanding to remove any remaining bits of plastic but apart of that it is a really handy tool.

1. V4 is the smaller version that's a bit more handy.

Creality

Ender 3

No

Yes

1.6

20 gyroid