From the new and very useful book "Die Württembergischen Medaillen 1864 - 1933 (einschließlich der Orden und Ehrenzeichen)" by Klein and Raff (English: The Württemberg medals 1864 - 1933, including the orders and decorations), that can, if still any are available, be ordered at Uwe Bretzendorfer.
Pages 112/113: 38 mm in diameter, portrait of king Karl, a big wreath around it, the suspension matches... seems to be such a medal by a Württemberg Kriegerverein!