Annnnnnd after 7+ years of silence... we're back!

What kind of brake system?

 

Never seen one like this before:

Took this photo a while ago:

A closer look reveals a gem of a name:

For the bikepackers:

Its tough to tell... but if I remember correctly, this is the cage of a Sram derailleur.  Marketing at its finest:

Great spot for a photo: