The Kenko Auto DG Extension Tubes are a set of three individually sized tubes compatible with Sony Alpha lenses. Use individually or stack multiple tubes together to enable existing Alpha lenses to focus closer than the normal minimum distance. The extension tubes create a set distance between the original lens and the sensor, ideal for creating macro images. The tube design is free of any additional elements, which allows the original optical quality of the Alpha lens to be maintained.The set contains one 12mm, 20mm and 36mm length tubes for Sony Alpha lenses. Combine each one as needed based on the level of magnification required.