Simple coat button with 4 slightly resessed holes - work nicely with a winter coat. Print flat on the bed and can be easily scaled if you need smaller or larger size.

Printed with Red Cosmic filament from Filamentive (https://www.filamentive.com/product/pla-rpla-750g-cosmic-red-3d-printer-filament-1-75mm/) - no supports or anything fancy needed!