500mm f/6.3 Manual Focus Telephoto Mirror Lens + 2x Teleconverter = 1000mm For Pentax K-S1, K-S2, K-m, K-r, K-x, K-3, K-5, K-5 II, IIs, K7, K10D, K20D, K-30, K-50, K100D, K110D, K-500 For Pentax K-S1, K-S2, K-m, K-r, K-x, K-01, K-3, K-5, K-5 II, K-5 IIs, K7, K10D, K20D, K-30, K-50, K100D, K110D, K-500, K200D, K1000, K2000, *istDS2, *istDS, *istDL2, *istDL, *istD, (K-Mount) Digital SLR Camera The 500mm f/6.3 Manual Focus Lens is a catadioptric mirror T-mount lens, precision manufactured in South Korea. -- White lens barrel helps prevent heat retention. 7 Elements in 6 Groups. -- Aperture is fixed at f/6.3. -- Focuses to 6.1' (1.86 m) 95MM Multi Coated UV Ultra Violet Filter: Protects lenses from dust, moisture, scratches, and other damage. These filters can be kept on the camera at all times. Provides basic reduction of ultraviolet light. Helps eliminate bluish cast in images The 2x Teleconverter is a high-quality that delivers enhanced telephoto versatility. It multiplies the focal length by 2x, providing an affordable and portable way to extend your cameras reach.