I just received the tiniest gun I have ever seen. I'm not an expert on guns but I am somewhat knowledgable. It is a little less than 5 inches in total length, with about a 1 1/2 inch barrel. It is a .22 single shot "derringer"? Engraved on it is a U with two symbols, each one on top of the other . I am sure that this gun isn't worth much value. I'm just curious as to what it is. Any help is appreciated.