Nikon AF-S DX NIKKOR 17-55mm f/2.8G IF-ED Zoom Lens with Auto Focus for Nikon DSLR Cameras Constant f2.8 3.2x zoom lens developed exclusively for use with Nikon DX Format, optimized for Nikon digital SLRs Dust and waterproof rubber sealing mount. Focal length : 17-55mm. Maximum Reproduction Ratio : 0.20x High optical performance by aspherical lenses and ED glass elements Silent Wave Motor enables ultra-high-speed autofocusing with exceptional accuracy and powerful super-quiet operation M/A mode for quick switching between autofocus and manual operation