A pair of SlingLink Turbo W1 power line Ethernet adapter.
Plug them into standard power outlet and the pair acts like an Ethernet cable.
The signal runs through the house's power line.
Does not work with power strip as it offers poor signal connectivity.
HomePlug compatible.

Model number: SL300-100
Part number: 162773

What you see in the photos are the actual units.
Very good condition. Tested working.