This is the Norwesco Heavy Duty Drainable Leg Tank - 3210 Gallon. When complete drainage is necessary, these are the tanks of choice. They are designed primarily for use on fertilizer and chemical nurse trailers. All Norwesco drainable leg tanks require full length bottom support as well as support bands. Our Norweso Horizontal Drainable Leg Tanks are constructed with a UV stabilized resin and a specific gravity rating of 1.9 (15.8 lbs per gallon).