Material: Maple Plywood, Acrylic base and optional cork Dimensions: Each coaster measures 8.6cm / 3.38 in. Quantity: This article includes 4 coasters with the selected options. Treatment: Finished and ready to use. This article is a quality-finished laser cut Japanese style set of 4 coasters. The coaster contains the wooden layer (the one with the pattern) and bellow the acrylic layer glued with a special super strong glue. If you want, you can add a cork base to protect the acrylic from scratching and also to avoid being slippery. Each layer measures 3mm high (0.11in). Two layers will be 6mm (0.23in) in total, 3 layers will be 9mm (0.35in) in total. Please select if you want 2 layer option or 3 layer option. You can also select the acrylic layer colour. The acrylic colour doesn't mean you'll be sent the same pattern. It only means it'll be sent 4 patterns with the same acrylic base colour. The item comes already mounted and ready to use. Not suitable for dishwasher.