poe splitter

Can I use something like this to power a tp-link POE switch ? So I can power 4 ip camera from one wire.

Hi I have a PTZ ip camera which is power by a POE injector. I assume the power its getting is 22w as this is what is specified by the camer maker. The Camera has a RCA plug for a mic so I ordered a simple mic which needs to be powered. Now I dont want to run another seperate power cable...