Sony SAL20TC 2x Teleconverter

This 2x teleconverter (SAL20TC) is compatible with the 70–200mm F2.8 G (SAL70200G) becoming an autofocus 140–400mm F5.6 super-telephoto zoom, the 300mm F2.8 G (SAL300F28G) becoming an autofocus 600mm F5.6 super-telephoto, and the 135mm F2.8 [4.5] STF (SAL135F28) becoming a manual-focus 270mm F5.6 [T9.0] telephoto lens.

Because the minimum shooting distance of the primary lens remains the same, the 2x teleconverter also effectively doubles the lens's magnification. In the case of a lens like the 135mm F2.8 [T4.5] STF, which normally offers 0.25x magnification, this means you get undiminished image quality with impressive 0.5x agnification. And although the maximum aperture of your primary lens is reduced by two f-stops when using a 2x teleconverter, you can overcome the problem of camera shake simply by boosting ISO sensitivity and utilizing the Super SteadyShot® image stabilization system built into your a System camera body.