Bloem 18" Charcoal Grecian Plastic Urn. This traditional style planter is perfect for both indoor and outdoor use. Made of durable plastic, it features a charcoal gray finish and a round shape. Measuring 18 inches in width, 15 inches in height, and 18 inches in depth, this urn has a potting capacity of 0.5347 cubic feet or 16 quarts.