The plug adaptor in the picture was used by a service family in Germany.
They were lucky
If adaptors must be used to convert UK style plugs to fit German sockets it is Essential that they are of an electrical rating that is enough for the load.
‘Travel Adaptors’ are intended to be used for short periods with small items such as razors or hairdryers or phone chargers.
They are Not Safe for Permanent use.
Unless the adapter is rated for at least 13 amps
marked with the CE mark
British Standard i.e. BS 8546:2016 + A1: 2018,
it can be Dangerous.
When any adaptors are in use, make sure they are Unplugged if unattended, even for short periods of time.
The incorrect use of plug adaptors can result in the melting of the pin holes in plug socket and in some cases result in the socket catching fire, which can have catastrophic effects.
IF IN DOUBT ASK YOUR HEM