I was ordering on Amazon anyway. (something for my husband shhh.) And the universal pen holder for the brother scan and cut was on sale for just over $10. (it usually runs $16 to $20) so I had to snag it while it was cheap instead of adding it to my Christmas list.
I haven’t actually used it in my machine yet, but I did test a bunch of pens for fit. It fits most of gel pens I have and the sharpie fine point.