The viewfinder magnifier M 1.4x enlarges the viewfinder image by two fifths and is recommended for focal lengths of 75 mm and above. This creates a viewfinder magnification of 1x, which enables comfortable binocular observation of the subject. The viewfinder magnifier is simply screwed into the viewfinder eyepiece of the Leica M and attached to the eyelet of the Leica M carrying strap using a safety chain. This protects it from loss and damage. A leather case is included for storage.

For the Leica M10 it is possible to use the eyepiece thread adapter (24001).