Cat Magnet for Fridge Door fits 6x3mm neodymium magnets. I used these:
Easy to print with 4 colors and AMS. I used Bambu Matte Ash Grey, Bambu Matte Charcoal Black, SUNLU - PLA+ Grey, SUNLU - PLA+ Beige(Skin)
Magnet holes are 1mm shallower so the magnet is easy to place. Use any superglue to fix them.