From a photo posted in the GOG thread (Girls on Guzzis), a lady was wearing a Ruby retro looking helmet.
I looked for information about the Ruby line, and found they were proposed by a company based in China.
These helmets are expensive, but after more research, it turns out the Ruby company based in China may not be the legitimate rights' owner of the brand.
This is the "About us" posted on what they claim as being the sole official Ruby Helmets market place: https://www.ateliers-ruby.com/pages/about-us
Succinctly, they say they are not manufacturing any helmet as of now, and all those are available from the Internet are not legitimate "Ruby" products.