.41 RF. 2.5" barrel length. SN: 7722. Blued metal finish to barrel, frame possibly silver plated at some point. Checkered walnut bird's head grips. Single action derringer pistol with hammer notch rear sight, German silver blade front sight, and turn-down swivel barrel. Markings include two-line Colt Hartford address marks. Frame is engraved with simple scroll to sides and straps.