Rare "Frankenau's Patent" five-shot, 5 mm pinfire revolver, double action Nickel-plated brass frame, stamped on the top "Frankenau's Patent", with black leather cheekpiece, opening on the right side on four leather compartments reinforced with nickel-plated brass pins. On the left side opening, it conceals a pinfire revolver. Round barrel of 17 mm. Round cylinder. Open frame. Crestless hammer. Loading door pivoting on the left side. Long external folding trigger. Iron rod plated in the lid. 11 x 7 x H 3 cm B.E. About 1880. (wear of use). Oscar FRANKENAU, inventor in Liege, patented this model in August 1877 in the USA, Great Britain and Germany.