Opteka 500mm f/6.3 (with 2X- 1000mm) Telephoto Mirror Lens for Pentax K-70, K-50, K-3 II, KP, K-1, K-S2, K-S1, K-500, K-30, K5 IIs, K-7, K-5, K-2, K20D, K100D, K110D and K10D Digital SLR Cameras

Opteka 500mm f/6.3 (with 2X- 1000mm) Telephoto...