lot 3 old Ball Ideal 1 pint mason jars w/ lightning lids, WWII vintage

Lot of three old Ball Ideal mason jars with glass caps and wire bail fasteners. These are 1 pint size and are square with rounded corners.

We've been told that this shape was introduced during World War Two by the war production board as a more efficient shape then the old round jars.

They do have some light rust to the wires.