There is currently a square reader version, and a Zettle version (printed). If you use another reader that I do not have listed (I'm getting one that uses Stripe so I will add that when I get it), let me know and I'll work the model around to fit your needs.
The back portion to stand business cards up can be customized in the center if you want, along with your business name or logo conveniently will fit in the oval on the bottom base portion in front of the qr code.
https://printer.tools/qrcode2stl/ This is the website I used for the QR code. 64mm x 64mm is the available space for the code on the paystation I would not recommend using text on the code or a border because it will mess with the overall dimensions once downloaded. Also a 2-3mm thickness is ideal.