Why do you think incremental Blocks are introduced in JF-17? to improve and introduce. JF-17 received IFR probe in Block II what does it mean?...If JF-17 is meant to have several Blocks it means better product in the future thus it would receive same technologies J-10B could get. From Pakistan point of view it is not easy under budgetary problems and bad economy to afford another Type that is why Pakistan chose to keep on buying F-16 when ever money available and continue with the improvements to JF-17 so maybe forget for next 10 Years anything else, JF-17s, F-16s and Mirage ROSE will continue.