How to get Steflos Prime Blueprint in Warframe?

Steflos Prime Blueprint is an item dropped from Void relics.
You can find the list of relics below, and click on the links to see how to get them.

Relics dropping Steflos Prime Blueprint

Other items:
Steflos Prime Barrel - Steflos Prime Receiver - Steflos Prime Stock
Steflos Blueprint - Steflos Stock - Steflos Barrel