This is a 38 centerfire S&W single action Second Model and is serial number 90648 and is matching numbers. The mechanical function is very good crisp and tight. The bore is very good with strong rifling but does have some traces of corrosion. It retains over 80% original nickel finish and the grip are sharp and crisp. They were made from 1877-1891. This was probably made 1889-1890.