Features:
Viltrox EF 1.4× EXTENDER is made of high quality coated optical glass with optical designing, which will increase the focal length of all Canon EF lens to 1.4 times.
Built-in metal contact, auto focus, can reach the data transmission between lens, teleconverter and camera.
EF 1.4× EXTENDER is specifically used for 100mm or more fixed focal length lens, such as 300mm f/2.8 lens and 200-500mm long lens perfect combination, can be used for fixed focus lens and a telephoto lens.
But is not recommended for use in less than 60mm of short-focus lens.
Comes with one front cover and one rear cover for effectively protecting lens and dust prevention.

Specifications:
Brand: Viltrox
Model: EF 1.4×
Mount Type: For Canon EF-Mount lens
Magnification: 1.4 times
Min. Stacking Focus Length: Equal to the original lens
Constitution of the Lens: 7 glasses, 3 groups
Focus Mode: Full auto focus
Lens Coating: Multi-coated
Front Cover: Camera cover
Rear cover: Lens dust cover
Diameter and Length: Approx. 72 * 28mm
Item Weight: Approx. 190g / 6.7oz
Package Size: 11 * 10.5 * 7.3cm / 4.3 * 4.1 * 2.9in
Package Weight: 317g / 11.2oz

Package List:
1 * Viltrox EF 1.4× Teleconverter

Note:
The teleconverter is not recommended for use in less than 60mm of short-focus lens.