It’s an Italian reproduction of a black powder 1872 Colt Open Top Revolver in .38 S&W Special. It fires modern .38 special non +P ammunition. This was the first purpose built Colt designed cartridge revolver made (original chambering was in .32 Colt Rimfire and Centerfire, .38 Colt Rimfire and Centerfire, and .44 Colt Rimfire and Centerfire, all in black powder. Unfortunately, the open top design was flawed as, like their predecessor cap and ball models, they tended to shoot "loose." The design only lasted for two years. It was replaced by the famous Colt Single Action in .45 Colt, .44-40 Winchester, .38-40 Winchester, and .32.20 Winchester, which had a much stronger integral top strap frame into which the barrel was screwed, ending the loose barrel problem forever.
Thanks, learned something new. I’m guessing Colt used some 1851/61 parts in the 1872.