ThinkBamboo 4" X 4" Bamboo Coasters - 2 X 6pc bundle pack - Slats and rods, Carbonized Natural Bamboo coasters, packaged 6 per set, 2 sets per bundle Coasters each measure approx 4" X 4" (10cm X 10cm) Constructed from flat slats and round matchstick rods of bamboo Bamboo is a highly renewable resource, and is ideal for coasters because it is natural, non-toxic, and durable. Great as wedding favors.