Compact, portable, HEPA filtration solution delivering air scrubbing/negative pressure air movement capabilities. Its two-stage design features a pre-filter and a high efficiency HEPA filter for outstanding air filtration in a wide range of industrial and construction related job applications. An optional activated carbon filter can replace the standard pre-filter to help absorb a wide range of volatile organic compounds (VOCs), smoke, plus other noxious odors and contaminants. A clean filter indicator light tells the operator when to change the filter to maintain optimum airflow and filtration. The unit comes with a variable speed motor for adjustable airflow rates up to 500.0 CFM. Capable of daisy-chaining multiple units together on a single circuit using the integral GFCI outlet and 12.0 Ampere breaker. In addition, the AF501 offers a 9.5” diameter inlet for maximum airflow, low power consumption and easy attachment of standard ventilation ducts for negative/evacuation air flow applications.