The Airbus S-24 (NATO reporting name: Siren) is a multirole jet fighter built and designed by French aerospace conglomerate Airbus and employed by the French Air Command, the Italian Air Force and the Danish Air Force. Introduced in 2006, it is the most cutting-edge fighter currently in use, with an expected service life of twenty-five years. Designed to supplement instead of replace the S-21 Sentinel, the Siren has had relatively low production, and fewer than 1,000 are currently in operation, although the French Air Command placed an order for 2,500 of the planes by 2020, when the Sentinel is planned to have been mostly phased out. The Siren's sister-plane is the S-8 Razor interceptor plane.