This 6Bit adapter ring also supports trap focus. First, set the camerafocus mode to AF - S. Then, while pressing the shutter fully, slowly turn the focus ring, when the focus is clear, the camera can quickly take a clear photo. Focus Indicator Function:This 6Bit adapter ring also supports the focus distance indicator function, set manual focus mode on the body, there will be two opposite triangular icons at the bottom left of the display, find out faster whether the focus point is in front of or behind the subject, take clear photos. Focal Length Identifying:with a Click Focal Length Dial,Uses a click focal length dial, it can better avoid changing the focal length on the dial by mistake during the use. When using a lens without the 6Bit contact, the focal length dial needs to be set to be consistent with the focal length of the lens. Press the reset button to record the focal length information; Use the lens with the 6Bit contact, there is no need to set the focal length dial. Press the reset button to record the focal length information. Compatible lens:M - mount lens Color: Black Material: Aviation Aluminum Package Contents: 1 x TTartisan M-Z 6Bit Adapter Ring