So I did a bit of research into these a while ago, I believe the seatposts were first used by Klein, they were made locally to Klein and had a strong affiliation with them. I believe they started production around 96-97, it wasn't until around 1999/2000 that the stems first came out, there is a fair bit about them online, Wikipedia etc, I had to do all this for a 1998 Klein build I was doing.