These buttons measure around 3 1/4" or 80mm and I have a number for sale in a range of different types of wood. (Number 12 is about 70mm) Being handmade, sizes may vary by a few millimetres.
I've seen them used as a feature on a scarf or bag and they'd be just great as a feature on a woollen hat. See the November 14th blog entry here

for a superb knitted hat pattern by Woolly Wormhead!
Please message me if you have a preference for a particular button (images are numbered).
Also... just recently I have been asked for sets of giant buttons to make wall decorations in the buyers' sewing rooms!

I can make any size in any of a great variety of types of wood. And I'll be repeating some of the already sold styles so please ask.

Questions? - I'll be happy to answer them!