This slate coaster is laser engraved with a topographic map of 4000 footer Mount Lincoln in the White Mountain National Forest of New Hampshire. The back of the coaster is laser engraved with the name and elevation of the mountain. The coasters measure roughly 4 inches by 4 inches and are approximately 1/4 of an inch thick. They come with cork pads on the bottom to protect your furniture. All Bay Slate Coaster products are handmade on Cape Cod from natural slate quarried in the United States. Please note that these are natural slate coasters so the edges and surface of the coasters will vary from coaster to coaster.