They're most likely sh!t!
I bought a set for my vintage CB650SC from an ebaY seller just like the one you listed...maybe even the same, not sure. The OEM application is non-drilled rotors and a set of new OEM's would cost $450 for the front set! I paid about the same for a new set of drilled rotors as what your auction runs. I got them in reasonable time and got them mounted up right away. Within DAYS of using them, the steel rusted. I don't think you could buy cheaper quality sh!t anywhere. The rust would burnish off where the pad wear was but once it sat overnite, it would rust over again and it wasn't just a surface oxidation, these pieces of sh!t would pit within days.
I pulled them off after about 2 weeks and put my OEM's back on as they were still good, I just wanted drilled discs more than anything. I sold them off to guy that was putting together a basket-case nighthawk after warning him about my experience. He wasn't concerned so good riddance to that cheap garbage!
Save your money and buy the quality EBC's or Galfer's or....any known reputable manufacturer. The ebaY versions were actually from Italy.