For Austria the records list Types C and F at 230 V and 50 Hz. At 230 V the supply matches what UK and European appliances expect, so no converter is needed.
The same socket system is used in Romania, Andorra, Serbia and Hungary, so one adapter covers all of them. Nearby but different: Ireland, the Isle of Man and Gibraltar – an adapter for Austria will not fit there. 31 of the 50 destinations in Europe share the plug types of Austria.
Protective earth
Grounded and ungrounded sockets may occur
Austria has sockets with a protective earth (Type F) and without (Type C). A plug that fits mechanically does not guarantee earthing.