I know I have had over 60 banty eggs in there with no problem. Somebody who also uses that brand once said that they have put over 80 small bantam eggs in. So I guess it is pretty much what you can fit in. I do not like putting them in the very corners or squashed up along the edges because I...
I've put quite a few more small eggs in them, hand turned them, and had them hatch fine. I do keep them out of the very corners, the hatch rate was similar to when there were fewer hand turned eggs. These were home eggs, not shipped.