Sigma 18-125mm f/3.5-5.6 DC IF Aspherical Zoom Lens for Nikon Digital SLR Cameras Nikon "G" mount; telephoto zoom lens Aspherical lens elements; The IF (Internal Focus) design allows for a non-rotating front barrel 18-125mm focal length f/3.5-5.6 maximum aperture Exclusively designed for use with digital SLR cameras