Introduction on how Power over Ethernet (PoE) works - see the attached PDF Data Sheet
5-port 10/100 Mbps PoE (PSE) Ethernet Switch
5 and 0-port 10/100 Mbps PoE (PSE) Ethernet Switch with +24 VDC Input
8-port Industrial 10/100 Mbps Ethernet with 4 or 8 port-PoE (PSE) Switch