This cool little device slides over the view finder of a OM film camera as shown for fine intricate work. I used it years ago for astro photography to get stars correctly focused. It boosts the image 1.2X or 2.5X. The eyepiece rotates to any angle and has a diopter adjustment. Not sure if it will fit a OM-D retro digital. You can try it if interested. Comes with case.