Just got some with my new work logo and custom die cut too. The stickers I have had from Sticker Mule before were outstanding quality. I expect these will be the same.
Site says: Put a pin in that
Upload your artwork and we'll create a custom acrylic pin. We use a solid, transparent, acrylic material that can be printed in full color and die cut to any shape. Each pin features a durable, steel butterfly clutch, allowing you to fasten your pin to your clothes or accessories.
As is often the case, buying it through the canadian website is slightly cheaper. $11.5 canadian dollars = ~$12.07 AUD