Dear Moderator: I did not list link to an external source because this image did not use one. All material come from the Visualization package that come with C4D this include the HDRI that made up the background of this image.

Don't forget to mention the background source
Otherwise, remove the background completely... it will make your model stand out more I think

The Material used are from C4D. The flowing material was used.
All material are from the Visualization Category of standard Material
From the Metal set LEAD, BRASS, CHROME, IRON
From the HDRI set HDRI_02

fantastic job, congrats

Superbly done - this is really something to look at and looks very realistic. I like the natural background selection.

Simply awesome!