The EnviroFin passive onsite wastewater treatment and dispersal system from Presby Environmental is designed to have a small footprint and ship easily, while maintaining and exceeding NSF/ANSI Standard 40 treatment. The effluent leaves the septic tank and enters the fin distribution unit, where it settles and breaks down suspended solids. Skimmer tabs located at the perforations prevent grease and suspended solids from leaving the FDU. The FDU distributes the effluent into each of the eight treatment fins, filled with coarse green plastic fibers, filtering and digesting more suspended solids while creating a massive bacteria treatment area. Each treatment fin has a perforated pipe functioning as an air duct across the top, providing oxygen to promote bacterial growth. The unit is buried in C-33 concrete sand and is installed with differential vents for airflow. It ships in a 2- by 4- by 2-foot box weighing less than 65 pounds. 800/473-5298; www.presbyenvironmental.com.