Each coaster measures 3 3/4? and is made of Bamboo.? You can also get the entire set of 6 matching engraved bamboo wood coasters and it will come with the holder.? The bamboo holder does not come with the set of 2 coasters. These make a very nice wedding, anniversary, birthday or Christmas gift since they can be personalized with your custom image or text.? Also make a great corporate gift since a company logo will look very nice on them too. You can also add this to our custom engraved whiskey glasses and get a matching engraving.