expression
made in (...)
Used as a set phrase, typically followed by a country name, to indicate the place of manufacture. Common on product labels and in commercial contexts.
この時計はメイドインスイスです。
This watch is made in Switzerland.
ラベルに「メイドインジャパン」と書いてある。
The label says 'Made in Japan'.
国産 means 'domestically produced' and is a native Japanese term, while メイドイン is a direct loan from English used in the specific phrase 'made in ...'.
Borrowed from English 'made in', used as a set phrase in Japanese.