This is the duty version of S&W's N frame 41 magnum.
It has long been out of production, and was available only in blue, and
in a 4 inch barrel length. This is one of the very few N frame Smiths which
had fixed sights, and the only fixed sight N frame in a magnum caliber.
The other fixed sight N frames are the old 38/44, and the
origonal model 1917.