The 640 series was originally introduced in 1995 as the first J-frame revolver chambered in the powerful .357 Magnum. The revolver features a double-action design with a robust steel frame that adds additional heft and strength to aid in handling the recoil of the more powerful magnum rounds. An internal hammer design reduces the overall profile of the 640 series while also reducing possible snagging during the draw. The Performance Center models feature enhanced double-action springs for a lighter, smoother trigger pull along with interchangeable tritium night sights for greater sight visibility in low light conditions. This model features a matte black finish and sports a 5-round capacity.