Made between 1966 and 1971, this is an aluminum frame version of the Model 40, with a ramp front sight and notch rear sight, a steel cylinder and barrel with a 3-screw frame, fully-concealed hammer and serrated grip safety. The barrel, cylinder, grip safety, sideplate screws, and later-style dished thumbpiece are nickel finished, the trigger is casehardened, and the frame is blue. Smooth round butt grips with S&W medallions. Complete with original blue S&W box numbered to gun.