The Álvaro de Bazán class (also known as the F100 class of frigates) are a new class of Aegis combat system-equipped air defense frigates entering service with the Spanish Navy. They are being built in the Spanish factory of Ferrol and are named after Admiral Álvaro de Bazán.The ships utilize American Aegis weapons technology allowing them to track hundreds of airborne targets simultaneously as part of its air defense network. The F100 Alvaro de Bazan class multirole frigate is one of the few non-US warships to carry the SPY-1D AEGIS system (Japan's Kongo class also uses SPY-1).