This item is no longer in production but you can order any of these as a special order that will take 6-8 weeks to make.
The coasters are about a 4.75" not perfect square. There are rubber feet on the back to protect table surfaces and a circle is carved into the clay so that the condensation doesn't roll off. This is a coaster that your cup will not stick to because it is not perfectly flat...the circle is also wide enough to place a bottle of wine on.