This is the Novoflex fully mechanical (no electronic connection) adapter for shooting Sony A-mount lenses on Sony NEX cameras. The adapter contains a mechanical aperture ring that allows you to adjust aperture on the lens by hand which may be an advantage in some work, particularly with video.
This adapter provides no electronic communication between the camera and lens. All focus adjustments must be made manually on the lens itself. The aperture selected via adapter will not be displayed on the camera, and it will not show up in the EXIF data.