PoE Injector for Rock Pi S

Hi, I have a Rock Pi S, a 50 meters ethernet cable (CAT 7) and I’m planing on buying its PoE HAT.
So I’m looking for a PoE injector in order to power and connect to my Rock Pi S.
However I don’t know what specifications to have for the PoE Injector (voltage and current). It seems like the typical offers are: 48V0.5A ; 24V1A ; 15V1A ; 12V1A
Thanks.

48V0.5A is the standard 802.3af or 802.3at PoE voltage, the rest are passive PoE. Check:

https://blog.netgear.com/blog/active-or-passive-poe-that-is-the-question/

Ok, Thank you very much.