European air-defence frigates: De Zeven Provinciën, Sachsen and Álvaro de Bazán
alvaro de Bazan class Air-defence frigate (Aegis) vs De Zeven Provincien class - frigates vs F124 Sachsen class - Air-defence frigate
Three frigates of 143 to 147 m, close in size and mission, to be recognised by their main radar and gun.