Here is the type I bought.What type of splitter was this?
The most suitable type would be an 'Active splitter' that would provide a 12V DC supply local to the camera as an alternative to using PoE for power, in case the PoE circuitry had failed.
Active PoE Splitter Powers Ethernets 24V to 12V 2A IEEE802.3af Standard Black UK | eBay
As an eBay Associate IPCamTalk earns from qualifying purchases.