Pair of old table mats 1940

Pair of silver metal table mats. 1940s. In good working order and presentation. Some traces of time for one (see photos). Almost identical, however, they do not have the same sizes of balls on the undersides. Presence of silver metal balls under the undersides of dishes. Stretchable, clean, stable and practical for use/rangement, they are also ideal for large tables! Dimensions of a folded underside: 34.5 cm length, width 6 cm, height 2 cm. Dimensions of an open underside: 23 cm square.