Add on a Tele Converter to double the focal lenght of a lens. The 300L provides optimum image quality when used with the 200 F/4 or longer telephoto lenses. This converter provide full aperture metering and mantain automatic exposure control in both aperture and shutter-priority modes. This converter also offers Achromatic lens coating. FEATURES: * Magnification: 2x * Construction: 5 elements in 3 groups * Metering: Full aperture metering; meter coupled with MC/MD lenses * Exposure factor: 4x * Weight: 8 7/16oz.