Handmade resin circuit board coaster made in your choice of shape (hexagon or square), coaster color and trace color. The coasters are relatively heat and scratch resistant but should be used with caution with very hot things. Each coaster also comes with a cork backing. The square coaster measures approximately 4 inches on each side (or 5.5 inches on a diagonal) and is about 0.5 inches tall (including the edge). The hexagon coaster measures approximately 2.25 inches on each side (or 4.5 inches on a diagonal) and is also about 0.5 inches tall (including the edge). Please note that due to the nature of resin small bubbles and minor imperfections may occur in the pouring and drying process. I do my best to get rid of them but it is not always possible.