http://velo-orange.blogspot.com/2006/11/atax-internally-expanding-seat-post.html
They did them on some Peugeots back in the day. I think the black one is plastic - Atax Poly-Pro
@gbj_tester started
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http://velo-orange.blogspot.com/2006/11/atax-internally-expanding-seat-post.html
They did them on some Peugeots back in the day. I think the black one is plastic - Atax Poly-Pro