I first saw these pots at a bonsai nursery in New England and was excited to find they are made in larger, deeper sizes suited for container gardening. Each of these containers has wonderful proportion and is the perfect size for a tabletop on the patio. Made primarily of mica with polyethylene and graphite, these containers are dense and provide a thermal effect that moderates temperatures to protect roots. The polyethylene provides durability; my friend in New England has had bonsai in these containers for over 10 years and graphite provides the stable color creating the appearance of a fine ceramic container without the expense or the breakage. These containers are a wonderful way to transition a young tree from a container to the garden or a larger container and enjoy them in the process.