Mayne Inc Freeport Patio Planter, 18 by 18-Inch, Black Our molded plastic planters are made from 100% high-grade polyethylene, double wall design This planter features a double wall design creating a water reservoir. Outside Dimensions: 18"L x 18"W x 20"H. Inside Dimensions: 13.75"L x 13.75"W x 13.5"D Water reservoir capacity is approximately 6.5 gallons (24.6 Liters) - approximately 8 gallon soil capacity The weather-proof and ultra-tough construction allows you to enjoy your planter all year long with very little winter preparation. The UV inhibitors within the resin allows for a long lasting fade-free performance. 15 Year Warranty  Residential Application, 5 Year Warranty  Commercial Application. Made in the USA.