This is a high quality M42-MAF Lens to Mount Adapter. You can use this camera adapter ring in conjunction with the camera adapters to complete the connection to a digital camera supporting a filter thread.                                    Features            New and high quality<br>Although the lens will fit physically， automatic diaphragm， auto-focusing， or any other functions will not operate correctly while using this adapter<br>It is able to focus to infinity<br>Made of aluminum (not plastic)<br>                                                            Specifications                        Dimensions          0.16 x 2.50 in (H x R)        <br>          Weight          0.28 oz        <br>          Color          Black        <br>                                                              Package Includes            1 x M42-MAF Lens to Mount Adapter<br>