Helen's Asian Kitchen's natural 12 inch bamboo steamer is handmade and securely assembled with bamboo pegs and bamboo lacing. Unlike wood, bamboo is a grass, so it's a renewable and sustainable resource. A bamboo steamer is designed to sit over another pot containing boiling water (specially designed steaming rings make it easy to steam on 11 inch or 13 inch diameter stockpots). As the water boils, the steam enters the steamer through the open slats in the bottom and is contained in the steamer by the lid. The bamboo steamer absorbs any condensation, keeping water from dripping back onto the food. When heated, it forms a hot container and, with the cover in place, can keep food warm for up to half an hour. The bamboo steamer is also an attractive serving piece and may be brought right to the table. Foods that are steamed require little or no added oils or fats, and they retain vitamins and minerals and cook quickly and evenly.