Durable seamless design resists breakage. All round-end tanks have an extra heavy duty, molded rim and an extra-deep sidewall rib design for additional strength. Heavy duty, molded-in aluminum drain fitting and 1 1/4" poly drain plug ensure a long-life. FDA food-grade approved poly, tested to -20 degrees F, corrosion-free impact resistant and recyclable. Premium UV Protection assures long life and resistance to color fade in outdoor use.