Mica Pota are made of 80% mica, 15% polyethylene and 5% graphite. Mica has a natural ability to stabilize the temperature of the soil in the pots. This promotes healthy root activity during the growing season and protects during the cold periods. The polyethylene bonds raw materials together and makes the pots tough and durable. Therefore the pots seldom break. Graphite gives color and prevents discoloring. Mica pots have the appearance of high quality unglazed ceramic pots but they are much less expensive. 19.5" x 11.25" x 2.0" OD 18.0" x 10.0" x 1.25" ID Dark brown color. Measures: OD:19.5" x 11.25" x 2.0" ID: 18.25" x 9.75" x 1.5" x