There is a lip on the underside of the lid. It is 13 1/4 inches, from outside of the lip to outside of lip on other side.
If it was made in the USA I would buy one. I would never use China cast iron again, from previous experience. Raise the price and make it here.
There was no problem with mine.
It is awfully heavy. If I owned a glass top, I probably wouldn’t risk it.