Novelty ArtStone Ella 12 in. black square self-watering planter has a built-in internal Water-Minder reservoir drainagesystem which rehydrates plants as needed. Made from a proprietary blend of resin and natural stone. Includes footed bottom for airflow. No need for saucer or tray. Keep rubber plug inserted for indoor use. Remove rubber plug for outdoor use. Frost and UV resistant.