This is an item from the inventory of my family's stationery store, which was in business around the 1950s. It's used to moisten stamps and revenue stamps, or to wet your fingertips for counting paper money. However, what's inside this product is not a natural sponge, but a rubber sponge. It has the characteristics of glass products from that era, such as small air bubbles and a rough surface. Diameter: 68mm, Height: 19mm.