500 Imp Gallon Horizontal Black Leg Tank Horizontal Leg Tanks are primarily used for transport and nursing applications. They also make great trailer mounted water tanks and work well for stationary applications. Leg Tanks feature molded-in legs to support the tank and act as "baffles" to reduce sloshing. See our website about our other size and application water tanks! Our Norwesco tanks are made out of rotationally molded linear, high-density polyethylene resin that provides outstanding environmental stress crack resistance. The resin is UV stabilized.