Zyxel poe 12 is a single port power over ethernet poe injector that infuses and transmits electricity through unused pairs 45 and 78 in cat 5 ethernet cables while data flows are carried by the other pairs 12 and 36 as such both power and data can be delivered to poe devices pd via a single cat 5 ethernet cable without extra power supply with the poe 12 non poe switches can now power ieee8023af compliant poe devices through an effective single cat 5 ethernet cable link up to