Mayne 4831-R Polyethylene Window Box, Red This window box features a double wall design creating a water reservoir. Mayne melded polyethylene planters are made from 100% high-grade polyethylene Includes 3 Steel wall mount brackets with a Black powder coated finish Outside dimensions: 48"L x 10"w x 11.5"H. Inside dimensions: 43"L x 8"W x 7.5"D.Water reservoir capacity is approximately 3.4 gallons (12.8 litters), holds approx. 5 gallons of soil The weather-proof and ultra-tough construction allows you to enjoy your window box all Year long with very little winter preparation 15 Year Warranty - residential application, 5 Year Warranty - commercial application made in the USA