On the listing
A powerline set with mesh working and Wi-Fi 5, given in the title as up to 1.2 Gbit/s; a home network extended over the mains wiring at up to 1200 Mbit/s, ready at any socket with no setup, named for mesh working with a FRITZ!Box; a wireless access point at up to 866 Mbit/s on Wi-Fi AC plus 400 Mbit/s on Wi-Fi N, with three gigabit LAN connections in total, two on the FRITZ!Powerline 1220 and one on the FRITZ!Powerline 1260, and WPS and WPA2 named; connections for a router, computer, printer, smart television, hi-fi, Blu-ray player, games console and other network devices, named for media streaming, high-definition video, large transfers, network storage and internet television; a box holding one FRITZ!Powerline 1260 with wireless, one FRITZ!Powerline 1220, two network leads and an installation guide; and a closing note that the casing may vary within the same model with no technical or functional difference between the variants.
Where the 1.2 gigabits are attached
The title puts it next to Wi-Fi 5. The first bullet puts 1200 Mbit/s next to the mains wiring. Two statements, two links, one number that looks like both. Both are reported here as printed. The second bullet then splits the wireless into 866 and 400, which does not match either of the first two and belongs to a third question entirely.
Three gigabit sockets across two units
Two on the 1220, one on the 1260. Written out unit by unit, which is unusual and useful: it says which box goes in the room with the equipment and which goes in the room that needs coverage. Most sets in this family print a total and leave the reader to divide it.
The access point at the far end
An 866 plus 400 access point with WPS and WPA2. What it is not is a mesh node in its own right; the mesh is named as something it does with a FRITZ!Box, and that router is therefore part of the specification rather than an accessory to it.
Before ordering
Ask which specification the mains link uses. The page names Wi-Fi twice and the powerline standard never, and it is the powerline standard that decides what a third adapter will pair with.
Not a kit for American outlets
This set is sold on the European Amazon stores, described as the German-language version, and has no Amazon.com listing. Powerline adapters plug straight into the wall, and a European unit is made for European outlets. For an American home, the TP-Link, NETGEAR, Tenda and ReadyNet kits on this shelf are the ones sold on Amazon.com.