Russian Defense Minister Sergey Shoigu said during the opening of a national youth forum at the MIGIMO University that China has agreed to buy anti-ship missile systems from Russia as well.
By Allocer (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons
They are most likely replenishments of the Kalibr-AShMs for their Kilo-class SSKs.