Canon's Extender EF 1.4x III and Extender EF 2x III multiply the focal lengths of most Canon normal, macro and telephoto lenses by a factor of 1.4x and 2x respectively.
Both extenders contain built-in microcomputers that provide seamless functionality between Canon (D)SLRs and lenses. Other features found on and within each of these new tele-extenders are Fluorine lens coatings and weather and dust-proof construction.
