Canon EF 1.4X II Extender Telephoto Accessory 1.4x telephoto extender for multiplying focal length of Canon 135mm or longer lenses Fits all 135mm or longer fixed focal length lenses and some 70-200mm telephoto lenses Preserves autofocus on any EOS camera when combined with f/4 or faster lens Weather-resistant construction and improved anti-reflective surfaces in the barrel Measures 2.9 inches in diameter and 1.1 inches long; weighs 7.8 ounces Compatibility: w/ Case LP811 For EF 70-200 f/2.8L, EF 70-200 f/2.8L IS, EF 70-200 f/2.8L IS II USM, EF 70-200 f/4L, EF 70-200 f/4L IS, EF 100-400 f/4.5-5.6L IS, EF 135 f/2L, EF 180 f/3.5L Macro, EF 200 f/1.8L, EF 200 f/2L IS, EF 200 f/2.8L II, EF 300 f/2.8L IS, EF 300 f/4L IS, EF 300 f/4L, EF 400 f/2.8L IS, EF 400 f/4 DO IS, EF 400 f/5.6L, EF 500 f/4L IS, EF 600 f/4L IS, EF 800 f/5.6L IS