DESC: The F500 Whole House HEPA Air Cleaner connects to the return air duct of a forced air system or can be independently ducted. The HEPA filter captures 99.97% of the particles from the air that passes through the filter. The F500 Whole House Filtration System includes HEPA filter, 2" pleated prefilter, carbon-odor filter and motor/blower. Isolation mounting straps and HEPA AIRWATCH Indicator are also included. F500A: Standard cabinet for mounting in conditioned spaces. F500B: Insulated cabinet for mounting in unconditioned spaces.