That appears to be a digital "back" for the r series. In other words you would take a leica 35mm r-series camera and remove the film chamber door (aka camera "back") and replace it with this attachment. You could use the same lenses, the only difference would be the "effective" focal length due to the difference in sample area. Pretty cool concept if you ask me, digital backs have been around a long time for medium format cameras but this looks like the first serious attempt to do it for a 35mm film camera. Quality wise you will probably still be better off with an all digital camera, but its still neat.