Power-over-Ethernet uses your LAN to send power via the network cable to whatever device you have connected at the other end, saving you the hassle of plugging the device in to both the network and to power. PoE lets you centralise your power supplies.
Home-brew PoE typically involves trimming back part of a LAN cable, separating out the relevant pairs of cable, cutting them, and soldering on a power socket so you can connect a plug-pack. That works fine, but it's ugly, fiddly, and takes time. Our 4-Channel Power-over-Ethernet Midspan Injector is the solution! Just unplug your LAN cables from your switch, plug them into the "device" ports on the injector, run short LAN cables from your switch to the "switch" ports on the injector, and plug in whatever wall-wart power supply you have handy. Done! No soldering required.