The ZONS^®eco duo offers virtually unparalleled versatility. The small wastewater treatment unit fits perfectly into single- or multiple-chamber systems. And since the retrofit packages are identical for both system types, they can even be adapted at a later date. How is that possible? Simply replace the mounting mechanisms and install - that's it. Tanks are available in both concrete and plastic variations. Dimensions and designs are variable depending on the needs of the customer.