build-your-own kits

noun
UK /ˌbɪld jɔːr ˈəʊn kɪts/
US /ˌbɪld jʊr ˈoʊn kɪts/

Sets of parts you put together yourself to make something.

My brother got a build-your-own kit to make a toy robot.


OTHER MEANINGS

2. Boxed sets sold for children to build simple models like cars or planes.

The store sells build-your-own kits for cars and planes.

3. Starter packs for learning electronics or coding by assembling parts.

She used a build-your-own kit to make a small alarm.

4. Furniture or toy packages that come in pieces for the buyer to assemble.

We bought a build-your-own kit for a bookshelf.