Manufacturer description: The Pro 300 family are designed specifically to be used with prime telephoto lenses of 100mm or above, such as 300 mm f/2.8 lenses, and work best with telephoto lenses of 200mm to 500mm. With the 2.0x, DGX full AF operation is possible with camera lenses having a maximum aperture of F2.8 or brighter. Kenko does not recommend them for zoom lenses that have a range starting under 50 mm.
|Lens mount||Canon EF, Nikon F (FX)|
|Weight||184 g (0.41 lb)|
|Length||36 mm (1.42″)|