Weather-resistant to handle damp, inclement conditions.</br>Flexible 4X zoom coverage in the telephoto range.</br>The PENTAX-original Quick-Shift Focus System allows instant switching from autofocus to manual focus operation.</br>An Extra-low Dispersion glass lens element and two aspherical lens elements offer superior sharpness with minimum chromatic and spherical aberration.</br>Simple and functional design improves operability and body-based depth of field control.</br></br>Product Description</br></br>Pentax 21870 DA 50-200mm F/4-5.6 AL Weather Resistant Lens</br><br/>http://www.amazon.com/gp/product/B002BSGUZI