In addition to the guns which destroyers have, a guided missile destoyer is usually equipped with two large missile magazines which store the missiles for the ship, usually in Vertical Launch Cells. Some guided missile destroyers contain powerful weapon system radars, like the United States’ Aegis combat system, and may be adopted for use in an anti-missile role or a ballistic missile defense role. This is especially true of navies which no longer operate cruisers; as other vessels must be adopted to fill in the gap.