Lectron (Raytheon electronic block kits)

Related:

https://en.wikipedia.org/wiki/Gakken_EX-System

https://en.wikipedia.org/wiki/Denshi_block

Most related children's "electronics lab" educational toys (at least in the US) would instead have components laid out on a thick cardboard top of a chassis, with the leads wired to spring terminals. You'd use included lengths of hookup wire between the terminals. (Solderless breadboards and loose components were available at Radio Shack, and promoted by the Forrest Mims books, but those weren't marketed as something you'd buy your kid for Christmas/birthday.)

Note that there are modern kits that are similar to this allowing making circuits by snapping parts together. For example the Elenco "Snapcircuits" system

https://elenco.com/snapcircuits/

$128 in 1967 money is worth approximately $1,172 today - not cheap for a kids' toy!

So that is what those things were I saw when I briefly joined De Electronenclub ('The Electrons Club' in Dutch) in the early 70's. I was around 7 years old and never got to do much with these but the concept fascinated me to no end. Later I got to fiddle with similar although more complex Fischertechnik blocks at a friend of mine (hey Erik!) but those were wired together where these things worked like magnetic dominoes.

I assume it was the Braun version I played with given that this was the Netherlands.

I remember having one of those, I think we got it from a garage sale.

I don't remember playing with it as much as the "NNN-in-One Experimenter Kit" versions. It may have been broken, incomplete, or simply beyond my level.

This was one of my better Christmas gifts as a child, and was mostly responsible for my eventual career as an electrical engineer.