Sigma 17-50mm f/2.8 EX DC OS HSM FLD Large Aperture Standard Zoom Lens for Pentax Digital DSLR Camera Sigma 17-50mm f/2.8 EX DC HSM Auto Focus Wide Angle Zoom Lens - Lens Hood (LH-825-03)- Front & Rear Lens Caps - Lens Case - Sigma 1 Year North and South America Limited Warranty (3 Year USA Extended Warranty for a Total of 4 Years from Date of Purchase) For use with smaller chip APS-c or 4/3 digital cameras only HSM (Hyper-Sonic Motor) ensures a quiet & high-speed auto focus FLD glass elements with performance equal to fluorite glass for compensate for color aberration Ultra compact with overall length of just 3.6"