A few months ago I bought this pair of fins, made by Semperit. It is called Hans Hass System, and I found similar fins only in very old dive equipment catalogs. Were they marketed in the US? I'm really proud of these and I wasn't brave enough to try them but I would like to know is it a rare item? The fins are in excellent condition, so first I thought it's a very late reproduction of the original fins- or maybe the owner hasn't ever used them.