https://www.cgtrader.com/3d-print-models/gadgets/other/starbucks-halloween-magnet
Starbucks Halloween Magnet, dimensions: 50.09 x 50.09 x 12.07mm or 1.97 x 1.97 x .48in
Scale up or down as needed but, the magnet listed for this piece requires the current scale to fit correctly.
Magnet source: https://www.kjmagnetics.com/proddetail.asp?prod=BC41
File is 1 piece @ 250k poly
If you need help with the file let me know.