If you need power for just one or two devices, instead of a Po E Switch, you can use a single ' Po E injector to add Po E to one Ethernet cable. Compared to a larger Po E switch, a Po E injector is more economonical if you need only a small number of Po E devices in a particular location (break even on cost is probably about 4 ports, though there is also a neatness factor of usin a switch). A Po E injector is mains powered & inserts Po E into the Ethernet cable.