The ACS is composed of the Aegis Weapon System (AWS), the fast-reaction component of the Aegis Anti-Aircraft Warfare (AAW) capability, along with the Phalanx Close In Weapon System (CIWS), and the Mark 41 Vertical Launch System. Mk 41 VLS is available in different versions that vary in size and weight. There are three lengths: for the self-defense version, for the tactical version, and for the strike version. The empty weight for an 8-cell module is for the self-defense version, for the tactical version, and for the strike version, thus incorporating anti-submarine warfare (ASW) systems and Tomahawk Land Attack Cruise Missiles (TLAM). Shipboard torpedo and naval gunnery systems are also integrated.