It's the largest I can remember in any binocular I've used. I usually have issues with narrow eyecups, so I tend to prefer wide eyecups, but oddly enough I found these eyecups not the easiest to use. Somehow (paradoxically) your eye has so much room in the FOV and the eyepiece lens to move around ,that the eye position becomes critical, and I found I could get some kidney beans. Strange. But then, I only used it briefly, maybe with time you can get used to it.
On the other hand, another thing I discoverd is that, just like with many wide field Porros I simply could not see the entire FOV, and I don't wear glasses. Hard as I tried, it was impossible. If I twisted the eyecups down fully... well then usability became somwhat compromised, especially for birding (unlike for landscape viewing). And then, in my unit the eyecups did not have very clear positions, it was hard to pick an intermediate position and get it to stay put.