" http://www.amazon.com/gp/product/B00OT0VCP4?tag=httpblogtrave-20
The Magnification 2 times
MountEF mountElectronically controlled
Lens construction 9elements in 5 groups
Dimensionsmaxdia length 55739mm
When Extender EF2X is attachedthe lens maximum aperture will be smaller by 2 stopIn the above two case the camera will compensate the exposure automatically
YONGNUO YN2.0X III YN-2.0X III Teleconverter Extender Auto Focus Lens for Canon EOS EF Lens"
