Review on Improved Oval Rotatable Eyecup Viewfinder for Sony A9II A7RIV A7RIII A7III | Replaces FDA-EP18 FDA-EP16 FDA-EP15 by Noah Lewis

The advantage of this eyecup is greatly exaggerated. Made of plastic rather than rubber, it's flexible but definitely not soft or pleasing to the eye. The aperture is smaller than the aperture in the viewfinder, so you have to wiggle it back and forth to get a full view, and often this position isn't the most comfortable for the eyes. Also, my A7III (probably other models as well) has grayed out various options like shutter speed, aperture, etc. that appear at the top and bottom of the viewfinder. and again you have to move your eyes up and down to see them. I tried this eyecup for about 20 minutes and then went back to the original eyecup.