Our products are made with 100% high-grade polyethylene resin. The resin used in this window box has built-in UV inhibitors that ensure it does not fade easily. Double wall design provides the soil with adequate insulation from surrounding weather conditions. Built-in water reservoir provides your plants with a consistent source of moisture. Manufacturer offers a 15-year residential warranty or a 5-year commercial warranty on this 4ft window box. Our products are proudly designed in Canada and made in the USA.