These coasters are handcrafted 4" squares and are about 3/8"-1/2" thick made from hardwoods of Maple, Cherry, and Walnut. The holders are made with a hardwood maple base and hardwood walnut sides. The base is fitted to your coasters. You can add an image to be engraved with an additional charge. In the description please put what custom design you would like, and how you would like your layout of wood ex: (Walnut/Maple/Cherry/Maple/Walnut or Walnut/Cherry/Maple/Cherry/Walnut).