This is a steampunk theme coaster set, each coaster has been laser cut and engraved to look like a gear/cog using 4mm thick oak veneer and is approximately 10cm x 10cm. The set comes with 4 coasters and a small holder to put them in as shown in the photos. This is a clever design and practical use for any coffee table and a great gift for any engineers, mechanics or anyone that likes to know how things work and the added bonus is a mat for their beverage. Please note, shading may differ from the photo slightly.