Smith & Wesson's unique scandium alloy high strength frames allow for the lightest revolvers capable of firing .357 S&W Magnum. Built on Smith & Wesson's popular J-frame, the M&P340 weighs less than a pound. The 340's scandium frame conceals a stainless steel cylinder that ensures long-lasting durability. The M&P340 comes standard with an XS Sights 24/7 Tritium night front sight. This model has no internal lock.