The Smith & Wesson Model 31-1 is a 6-shot, .32 S&W Long caliber revolver built on the J-frame (after 1961), featuring a square butt, fixed sights, and available with 2, 3, 3.25, or 4-inch barrels. Manufactured between 1961 and 1991, this "Regulation Police" variant is known for low recoil, high reliability, and a smooth trigger, making it ideal for target shooting or concealed carry. 
This Model 31-1 is in very good condition. Serial number: H61858
Key details about the Smith & Wesson Model 31-1 include:  
Engineering Changes: The "-1" designation indicates the transition from the older "Improved I-frame" to the stronger J-frame, which started in 1961.
Chambering: Designed for .32 S&W Long, but capable of firing .32 S&W (short).
Physical Features: Carbon steel construction with blued or nickel finishes, featuring a serrated ramp front sight and a square-notch rear sight.
Production Era: Produced from 1961 to approximately 1991. Serial numbers with an "H" prefix began in 1969.
Usage: Often considered a compact alternative for users preferring less recoil than the .38 Special J-frames.