The Leica Viewfinder Magnifier M 1.25x magnifies the viewfinder image by one quarter. It provides a major aide in framing the subject at focal lengths above 50 mm. The viewfinder 1.25x is recommended for focal lengths of 50 mm or more. By magnifying the rangefinder images, it greatly enhances focusing accuracy, especially when shooting at telephoto focal lengths. The viewfinder is simply screwed into the viewfinder ocular of the Leica M. A small chain attached to the Leica M's carrying strap eyelet prevents it from being lost or damaged. A leather pouch is supplied for safekeeping when it's not attached.