Su-35 would give China technology for developing J-11C /...

In Russia Everything Is For Sale-- Strategy Page April 11, 2013: After more than a year of haggling over the details, Russia has agreed to sell China 24 Su-35 fighters. The big obstacle to this sale was the Chinese inability to assure Russia that the new Russian technology in these aircraft would not be stolen by Chinese aviation firms. Apparently a mutually agreeable compromise was worked out.

China J-11 fighter