Slide outs- how do they work?

[SactoSteve]

I have been curious about what the structural elements of the slideouts are and how they worked. Not the drive mechanism that moves the box, there is plenty on that.
An idle curiousity but i’m interested in what must be some sort of sliding support mechanism, like a drawer slide but beefy. I figured it would be an easy google, but I am coming up empty.

Any body?

-steve