Via Egami Blog (Japanese)This one, for what I have seen for the first time, can change the back focus distance so as to make the lens short-sighted (for macro purpose) if required. The above adaptor is for Leica M-mount lens to Sony NEX E-mount. Below are some more additional information about the possibilities of the adaptor when used with particular Leica M lenses:-http://leicarumors.com/2011/
