Roto-molded coolers are manufactured using a very specific rotational mold process wherein we utilize high end molded plastic (Polyethylene) that creates a continuous and thick cooler wall. This roto-molding process, combined with our extra thick and uninterrupted layers of insulation, ensures that Blue Coolers will keep your ice, drinks, food and whatever else, cold and fresh for the maximum amount of time. Moreover, you will not find a more durable, bear-proof cooler on the market.