An almost certainly 'New Old Stock' French manufactured Klaxon Horn, 6 Volt, Model 'ETF 4D'. I have cleaned and repainted in gloss black the case, however the inside was pristine and showed no sign of any use. The horn worked well when tested some 6 months ago.
Broken down. Not working. Could bake a working engine from the 2. Found in grandfathers / uncles garage along with large amount of other de Dion parts..