N910p cert file one in 2

HI everyone,
I am a noob but and now was succesfull to write a cert of N910u on N910p running 5.1.1

My question is , if i buy a clean cert from ebay then can i use it for two different phone. My main concern is the cert file i wrote was a activated one which i got for free. Metropcs could not use it but in swappa it says it is not blacklisted.
Any help in this matter would be greatly appreciated. too add more, Can i use a certfile compatible with SM-N910A SM-N910K SM-N910L SM-N910H SM-N910S or SM-N910T or SM-N910U

This was listed in ebay and have to be sure before i purchase it