This is the JJC Reversing Ring Four Thirds Fit 52mm [JU1252M] This is a reversing ring for 4/3 mount cameras with a 52mm filter thread. This reversing ring allows the photographer to fit a lens with a 52mm filter thread (of any brand) onto a 4/3 mount camera. One side of the ring has the fitting for the lens mount and the other side has a 52mm filter thread to attach to the lens. Fitting a lens reversed onto the camera will often turn it into an effective macro lens. The effect will vary from lens to lens. Since the lens is fitted reversed, there will be no control of the lens from the camera. It is important that a lens is used where the aperture can be controlled manually. Older lenses are often ideal for this use as they usually have an adjustable aperture ring. As the lens attaches using the filter ring, it is easy to mount any brand lens this way. ...Contact us if you need more help.