Only China builds large class J-20, medium class J-10B, small class JF-17. No other country has a complete line up like China does. CAC is the only company that incorporates DSI on large multi role jets, medium multi role jets, small multi role jets. No other company does so. DSI is round bump. Most effective at deflecting incoming radio away from engine. And no splitter means no gap between intake and main fuselage which means much less RCS.