This 3/16" black lava rock cinder enhances plant health by improving drainage and root aeration in bonsai, succulents, cacti, and other potted plants. Its rich black color doubles as a decorative top dressing that makes containers stand out while supporting strong root development. Packaged in a convenient 2.2 liter (2 quart) bag, it is easy to handle, mix into soil, and store between uses.