The Pulsar® 73290 Precision Duo Pool Maintenance System consists of two Pulsar Precision pool water maintenance units, which can be connected to run simultaneously off of a single chemical / ORP control (sold separately). Useful for high-demand or large commercial pools, this chemical-balancing systems helps ensure hassle-free, consistent pool water cleanliness and clarity. While a variety of usage factors will affect output, this dual-unit system is rated for treating pools ranging from 800,000 – 1,500,000 gal, when used as directed.