They keep it well hidden. I wound up sending Todson (US importer) an e-mail and they told me the secret code. Not the most friendly set up.
From my e-mail:
Response:

Hi,

You may purchase that replacement part from the Todson Online Store: http://www.todson.com/store, under part number: 60001004

Happy riding!

I just clicked on the store link. It's down, but they have an 800 number:
800-213-4561