I've been selling giant 8cm (3inch) wooden buttons in my shops for a while now...
They're massive, but my newest addition to my supplies range makes them look like mere babies: HUGE 12.5cm (5 inch) buttons!
King of the buttons! Buttonzilla! Call it what you want, this is one big button!
I'm not sure what kind of sewing project would need a button this big, but they look pretty amazing on their own and would look fab on display in a craft room.
They're now available from my Etsy and Folksy shops.