 The 4" heavy barelled version, introduced in 1974, became a favorite with many police agencies.Five variants were made for NYPD and these revolvers are marked "NY1" as opposed to the more common "NYCPD" marking for department issued guns as these were intended to be purchased by individual officers.It was the only stainless steel revolver authorized for use by NYPD as well as the last revolver approved for use being replaced by 9mm semiautomatic pistols in 1993.