I bought the product second-hand from someone I know and it is too early (it will take 1-2 years) to test and evaluate it properly and sufficiently. However, I am writing here to upload the photo (screenshot) from the User Manual and Warnings, which is also available as a PDF on the manufacturer's website, and I believe it will be very useful and informative for any prospective buyer.

(Manufacturer's page: https://www.brennenstuhl.com/en-DE/products/extension-leads/secure-tec-19.500a-extension-lead-with-surge-protection-acoustic-6-way-anthracite-3m-h05vv-f-3g1-5

(P.S. The only reason I am preemptively removing one star is that I would have preferred there to be protection sockets for: 1. the telephone-modem line, and 2. the TV antenna cable, so that the coverage would be more complete.
:
Let us keep in mind – with my humble electrical knowledge [as the German manufacturer also states] – that ALL these single/multi-socket "safety" power strips on the market are ONLY the LAST LINK in a chain of a SAFETY SYSTEM that should include:
* 1. FOUNDATION EARTHING (at the "feet" of the building's foundations – according to ELOT specifications – rising from the lightwell shaft, through the rebar in the columns up to the roof and connected – properly – with correct installation...
* 2. LIGHTNING ROD.
* 3. The appropriate detailed and load-bearing wiring that will end in each apartment at: 3a). Safety relay and 3b). Type 2 Surge Protection Relay (at least).
*4. The various safety multi/single-socket strips we use are ONLY the FOURTH LINK in the above protection chain.
*** IF the first 3 links are missing... which my relevant knowledge tells me are missing from 98.5% of homes nationwide, it means we are simply... lucky!!

(IF I wrote this whole long comment here, I did it to contribute a little to the knowledge of... ? What should someone EXPECT from such products, partly ALSO AS... A VICTIM... of a lightning strike (sudden summer storm in a big city)
(which I hope happens to no one => to take the necessary measures,... where a power strip and a relay are ONLY the last link.)
Sorry for the lengthy comment.