The RIM-162 Evolved SeaSparrow Missile (ESSM) is a development of the RIM-7 Sea Sparrow missile used to protect ships from attacking missiles and aircraft. ESSM is designed to counter supersonic maneuvering anti-ship missiles. ESSM also has the ability to be "quad-packed" in the Mk 41 VLS system, allowing up to four ESSMs to be carried in a single cell.