Snyder 180 Gal Cubetainer Oil Stacker is constructed from Virgin High Density FDA compliant Polyethylene Resin. With a convenient center fill port, their standard footprint design makes them stackable in any combination. Plus, there is no need for conversion brackets. The translucent tank is molded in level markers allow for visual level inspection without the need for external site gauges. Uniform Stacking Combinations for level shelving. Tanks can be stacked in a variety of size combinations to accommodate different volume requirements within the exact same space.