Patented in 1876 in both the US and UK, the Frankenau purse gun was a very small 5-shot, 5mm pinfire revolver hidden inside what appeared to be a normal small coin purse. One side of the purse would even open, with several accordion pockets, allowing to to be used for its nominal purpose. The other side contained the revolver, with a hinged plate covering the muzzle and a trigger which would fold up into the body of the case when not in use. Few were sold, and most saw a lot of use, making them pretty unusual to find today.