Septic system vents from Pagoda Vent Company passively ventilate onsite system components. They work in conjunction with the roof vent as air intakes, creating a draft through the system that clears gases and pressure within the system. They preserve concrete component integrity by diminishing microbial-induced corrosion. The vents aesthetically blend into the landscape, are lightweight and will not fade or rust. An optional odor control filter cartridge is concealed in the unit. 888/864-1468; www.pagodavent.com.