Looks to be pretty straight forward. A sliding shaft suspension post with a no set back seat rails clamp. Mid/late 1990s saw a lot of this kind of stuff.

My issue with this post is that on center clamp with no set back. It either places the seat forward of the usual set back posts position or results in the seat being clamped at the very front of the seat rails. Both might be OK or not. For me I like my set back (and in this use of the term I mean the distance between a vertical line extending up from the BB center to past the front tip of the seat and that tip of that seat) to be in a narrow range. In my case using this on center type of post would result in the seat clamped at the rails forward portion and thus creating a lot of leverage for the load on the seat (my butt) to act on the rails. I've seen way too many bent seat rails from this to want this set up. Your experience might be different. Andy