All four magazines chambered for 5.56 mm. 1) KCI Inc. 100 round drum magazine with case, manual, loading tool, and two tubes of lubricant. 2) KCI Inc. 100 round drum magazine with case, loading tool, and two tubes of lubricant. 3) KX Series 50 round magazine with case. 4) KX Series 50 round magazine with case and tube of lubricant.