RainbowImaging AF Confirm M42 42mm Screw Mount lens to Sony Minolta DSLR Camera adapter Ring for A900 A850 A700 A75 A65 A55 A35 A33 A580 A390 A380 A350 A330 A300 A290 A230 A200 A100 The ring allows M42 Screw Mount lenses (Carl Zeiss, Pentax, Praktica, Mamiya) to be used on Minolta AF mount cameras (film SLR and digital SLR) The electric chip will help the camera to confirm whther the focus is correct. When the focus is correct, it will "BEEP" to confirm it. AF focus is not available. User need to focus and adjust aperture manually. It is possible to use Macro rings and other accessories For A900 A850 A700 A75 A65 A55 A35 A33 A580 A390 A380 A350 A330 A300 A290 A230 A200 A100