Ideal for press, sports and nature photography, this compact extender increases the focal length of Canon L-series telephoto or telephoto zoom lens\' by a factor of 1.4x, with higher AF accuracy and improved communication between camera and lens. Benefits Extends the master lens focal length by 1.4x Outstanding image quality Highly resistant to dust and water Improved communication between lens and camera Optimised lens coatings Compatible with L-Series telephoto and telephoto zoom lenses Compatibility EF 400mm f/4 DO IS II USM EF 400mm f/5.6L USM EF 500mm f/4L IS USM EF 400mm f/2.8L IS III USM EF 400mm f/4 DO IS USM EF 500mm f/4L IS II USM EF 600mm f/4L IS USM EF 600mm f/4L IS II USM EF 600mm f/4L IS III USM EF 200mm f/2L IS USM EF 135mm f/2L USM EF 800mm f/5.6L IS USM EF 200mm f/2.8L II USM EF 300mm f/4L IS USM EF 400mm f/2.8L IS USM EF 300mm f/2.8L IS USM EF 300mm f/2.8L IS II USM EF 400mm f/2.8L IS II USM EF 180mm f/3.5L Macro USM EF 70200mm f/2.8L IS II USM EF 70200mm f/2.8L IS III USM EF 70200mm f/2.8L USM EF 70200mm f/4L IS USM EF 70200mm f/4L IS II USM EF 70200mm f/4L USM EF 100400mm f/4.5 5.6L IS II USM EF 100400mm f/4.5 5.6L IS USM EF 200400mm f/4L IS USM Extender 1.4x