The devices provide Network Connections that use power lines, so you can do without additional cables and their laying. We used this to connect our computer to the router, which also attach the printer to the router. The boxes are shown one was attached to an ordinary electrical outlet near your router and via the supplied network cable (length 200 cm) connected to this, the other came into the socket near the computer and was also connected wired so. The rest happened by itself, the connection was just there, without further action on our part. You just have to make sure (or hope) that both outlets belong to the same power line. One can state it probably the fuse box: The sockets that are simultaneously energized during boring a security belong together. The data line works great, stable, full bandwidth is there, even printing goes smoothly.
The device also offers the possibility to make the line eavesdropping by printing on both devices in short distance knobs (see instructions provided). Thus, the addition of further devices in the network is excluded (in a high-rise strongly recommended). If one wants later but take another device in the network, you would have to perform a reset and then build the network anew. The possibility in principle is given, but you then need course another set of connection devices.
The individual boxes are about the size of a smaller power supply, make quality impression, although they are made of plastic.
Unlike a network cable, however, they draw current. The part of the printer remains continuously active.