Seatpost and clamp for a Look 586?

[Kingson]

like the one in this picture:

https://buycycle.com/en-us/bike/defa...403862ab-73946

are these proprietary seaposts and clamps? i can't seem to find one, when i do a search.
is there an aftermarket seatpost?

[Tychom]

It's a Look RSP seatpost and clamp, aero shape. I think these came in on later or maybe just certain models of the 586.

Apparently Look E Post compatible - I'm not really up on my Look stuff but I figure it's compatible with ISPs that were cut too short also.

But as I say above, I think certain 586 came with these already installed (could be wrong! But I've certainly seen many 586 with them).