Where does “вставной” come from?

вставной (Russian) comes from Russian вставить, from Russian в-, from Old Church Slavonic въ-, from Proto-Slavic vъ(n)-, from Proto-Indo-European h₁én — in.

вставной (Russian): insert, insertion; plug-in; false, artificial

Definitions

insert, insertion; plug-in; false, artificial

Ancestry of “вставной”, step by step

Step	Language	Word	Meaning
1	Russian	вставить	to insert, to put in
2	Russian	в-	in, into
3	Old Church Slavonic	въ-	in, into describing an action of moving inside of something
4	Proto-Slavic	vъ(n)-	—
5	Proto-Indo-European	h₁én	in

Every word from Proto-Indo-European h₁én →Every word from Russian в- →Every word from Proto-Slavic vъ(n)- →