I'm an electrician and when I renovate an electrical installation in a dwelling, this tool is ideal for testing compulsory VDI network in the NF-C 15-100. Very practical to test the continuity and order of wiring RJ45 plugs between the table and the room.
Also works on long cables (50, 70m). I could test an entire network of lines in offices and thus regain patch bays connections - jacks. A colleague and a walkie-talkie are useful in this case ...