This is for a bag of 100 count brass manufactured by CORBON that are Nickel Plated Brass, used for testing. The Brass was tumbled and inspected for damage.
“Once fired brass” is an industry term that describes fired brass cases. Previously fired brass could have minor dents, dings, slightly bent mouths, or other slight imperfections. Most of these flaws can be easily removed during resizing or will be shot out upon your first firing.