A set of six bamboo coasters in a bamboo container with a steel bottle opener. Bamboo is a strong and solid material, and is highly sustainable, because of the rapid pace at which it grows. 12 ( l ) x 7 ( w ) x 9 ( h ) cm coaster diameter: 10 ( d ) cm bamboo & steel 6 bamboo coasters packaged in a natural kraft Okiyo gift box As bamboo is a natural material, there will be variation in the appearance in one product compared with the next or within similar items in a set.