The Kontrol Kube Negative Air Machine offers a revolutionary combination of power, efficacy and convenience. The Negative Air Machine weighs just 44 lbs, while delivering a variable speed up to 500 CFM with HEPA filter installed. The Kontrol Kube Complete Negative Air Machine also comes equipped with a DOP Stage 2 First Pass Pre-filter ensure one pass HEPA filtration for air clearance every time.