Sony SAL-20TC 2.0x Teleconverter Lens for Sony Alpha Digital SLR Camera 2x teleconverter lens for extending photographic range of primary lens Lets you cover more distance and capture more subjects without changing lenses Preserves both accuracy and image quality of primary lens for superb performance Compatible with Sony G series 70-200mm, G series 300mm, and 135mm STF lenses Measures 2.51 inches in diameter and 1.71 inches long; weighs 0.44 pounds