Both the slightly thicker Schuko plug my 10 outlet, as well as the "flatter" plug from eg most phone chargers sitting firmly fitting the adapter. Also the Adapter sat even within the 3-pin socket at the hotel without much play firmly.
The travel adapter met thus to 100% its purpose. I would definitely buy it again if the current would give up his spirit. A second one does not need the entrainment of a multiple socket for ease of use certainly.
The price fits my opinion also, therefore, a recommendation on my part.