German gymnastics association buckle.(Kasten-Koppelschlossen Deutscher Turnerbund). Early 1930s. Maker (Hersteller) : L.(Logo) F. (Linden & Funk, Iserlohn), ges. gesch. - shortcut for (gesetzlich geschützt) (protected by law).Steel buckle. Buckle catch, prong bar and dual prongs are made of colored metal (brass).Good condition. As the pictures shown.