The 2%2E0X APO Tele Converter EX DG from Sigma is mounted between the camera body and the lens to increase the focal length of your camera by 2%2E0X%2E Featuring focal length of 2%2E0X and aperture coupling range of F2%2E8 %2D F32%2C the APO Tele Converter EX decreases the effective aperture by two F%2Dstops%2E This tele%2Dconverter employs lens coating technology to reduce both flare and ghosting%2E Compact and lightweight%2C this tele%2Dconverter is a convenient way of converting lenses into long focal%2Dlength lenses%2C therefore ensuring that those unexpected opportunities are not missed%2E The 2%2E0X APO Tele Converter EX DG is specifically designed for Select PENTAX Mounts%2E