Natural Hog Casings for Sausage - Full Hank

I do not see on the bag or in the product description - are these guaranteed to come from only hogs raised in the U.S.?

What size (diameter) are these casings?

Are these hanks of natural hog casings stored in a refrigerated room? do these not have to be stored refrigerated?

Do these casings have to be soaked for 12 + hours? I have seen different instructions ranging from the 12 hrs to an hour