The high performance optical construction of 21 elements in 14 groups includes five ED lenses and one Super ED lens to help reduce chromatic aberration that often occurs in telephoto lenses. As a result, it delivers the highest image quality in its class. The lens has been designed for handheld shooting with a 5.0-stop image stabilisation system and weighs less than 1.4kg. Linear motor for fast autofocusing makes it perfect for shooting fast-moving subjects including aircraft and motorsports. Focal length: 100-400mm max. Aperture: f4.5 (wide) - f5.6 (telephoto) min. Aperture: f22 weather resistant coating. Model number 16501109.