This is a 3rd Model Colt Derringer which is also known as the Thuer Model Derringer. Caliber is .41 Rimfire with 2.5" round barrel. Brass frame is nickel plated with 92% remaining. Left side of frame marked "41 CAL". Barrel was originally blued and has turned to a dark gray patina with "COLT" in script stamped on the top of the barrel. Hammer, trigger, and screws appear to have been fire blued with good traces remaining on several of the screws and protected areas of the hammer. Screws have excellent slots. The wooden grips show a fair bit of use but remain solid. They appear to be made of English or French walnut and retain 40-50% original varnish. Very strong mechanics. Hammer works on half and full cock. Barrel still latches quite tightly to the frame and the ejector works. Bore is Fair to Poor...with worn rifling and some scattered pits...but no rings or bulges. A very presentable example of an early Colt Single Shot Deringer with nice contrast between the original nickel on the frame, reddish grips, and traces of blue on the balance of the gun.