X31II Anti-radiation missile, the imported Russian KH-31P ARM (Anti Radiation Missile) on attack.

In 2005, China imported 200 X31II ARM for its Su-30MKK fleet to perform SEAD missions. However, the performance of the missile was not as well as advertised which led to the replacement of the entire seeker. The improved Chinese multi-band seeker covers enemy radars operating between 2 to 18 GHz and a CEP of 8 to 10 meters and given the new designation of YJ-91.The YJ-91 has been integrated