unverändertem
Unverändertem is the dative singular form of the German adjective unverändert. It is used before a masculine or neuter noun in the dative case when the noun is not accompanied by a determiner that triggers a weaker ending, i.e., in strong declension. The form signals that the described state or attribute remains unchanged.
The adjective unverändert itself means unchanged or unmodified, formed from the prefix un- attached to verändert
For contrast, when a definite article is present, the ending changes to the weak form, as in