The XD-S is the first single-stack polymer framed pistol from Springfield Armory. In addition to the inherently slim nature of the design, the frame is a short sub-compact style, and the barrel is just 3.3 inches. The XD-S Single Stack seems to disappear when you carry it. X-Tension magazine (7 rounds .45 ACP, 9 rounds 9mm). The fiber optic front sight and white-dot rear sight align quickly and provide a clear sight picture for accurate shooting. The XD-S Single Stack also includes the Ultra Safety Assurance (USA) Action Trigger System, loaded chamber indicator, firing pin block, and grip safety that make the entire family of XD pistols safe and easy to use. Used and in excellent condition.