The Mark IV features a simple, one-button takedown for quick and easy field-stripping. Features a lightweight, ventilated, aerospace-grade aluminum receiver and a tensioned stainless steel barrel; contoured ejection port; an adjustable rear sight and a factory-installed Picatinny rail for easy mounting of optics; ambidextrous manual safety can be converted to left-side only with included washer; conveniently located push-button magazine release on the left side of the frame; Includes two magazines.