Sigma 18-250mm f3.5-6.3 DC MACRO HSM Lens with UV, CPL, FLD, ND4 and +10 Macro Filters for Pentax K-S1, K-500, K-50, K-30, K5 IIs, K-7, K-5, K-3, K-2, K-X, K20D, K100D, K110D and K10D Digital SLR Cameras 18-250mm focal length, only compatible with APS-C DSLRs (see title) 27-375mm equivalent focal length on APS-C cameras, 28.8-400mm equivalent focal length on APS-C cameras HSM (Hyper-Sonic Motor) ensures a quiet and high-speed auto focus Micromotor-type AF motor with full-time manual focusing Image stabilization, Up to 4 stops