Metabones Contarex to Sony NEX Adapter MB_CX-E-BM1 Both camera-side and lens-side of the adapter are made of brass, precision-machined and plated with chromium.Satin surface finish - just like your OEM lens and camera mounts.Precise fit and solid connection - lens has no play, gap or wiggling when mounted on adapter and no adjustments are required to fit your lens.Designed to reach infinity focus while maintaining the correct registration distance required to maintain optical quality of CRC lenses or lenses with floating elements. Metabones adapters have the following additional features True electronic integration of aperture diaphragm - let camera automatically choose aperture in P or S exposure modes, or dial in yourself on the camera body in A or M modes.EXIF data such as lens identification, focal length and aperture.