I'm assuming you talking about http://www.jaycar.com.au/productView.asp?ID=XC4254&keywords=poe&form=KEYWORD
that's a non standard midspan injector(aka no 802.3af) your etherten supports either, though it seems anything more than just running 12v over the unused pairs requires an extra board. Mind you that part from jarcar is not a hub/switch it takes 4 ports on your networking kit to connect but it does not care if they are poe as 802.3af will not work through it. If you want it to run while your main kit is off a cheap 5 port 100bt switch would do. Mind you non 802.3af poe injectors are a couple of bucks on ebay it's literary just wiring up a dc power supply to unused pins and can be done by clipping those wires and connecting them to a 2.1mm jack or similar.