This is a thick heavy glass lid. I thought it was Pyrex but it doesn't have a name on it. All it says is Mexico 3.  I don't know what that means. It measures 12 inches from edge to edge. It has an inner lip that is 11 1/4 inch that goes inside the pot. It is about 3 or 4 inches high, see pictures. Very heavy nice lid. Tempered glass. Used but no damage. Check postage, its heavy.