These were off-road machines built by Nauder, the French importer of Sachs, from c.1981 to 1986.
The logo looks like "VSN", but is in fact a stylised triangle followed by SN. Models included SN 250GS 1981, Sachs Nauder 125 MX 1982 and SN 250 GSB 1986. They had dual rear shocks possibly by Fournales. Late models had disc brakes.
Sources: forum posts, period advertising.
