I love these buttons!
They are such a striking late Deco styling and so typical of those times, highly functional and versatile. For they can be used both as a sew-through or a shank button. Ingenious!
The main body of each button is a dark burgundy red plastic with a brighter red insert with tubular shank. The buttons are approx 28 mm diameter. Most are in excellent condition although the red insert is starting to lift just a little at the edge on a couple of them (this is very slight and could almost certainly be restored.)