Oransi Multi-Carbon Air Purifier Same filters used in containment units and in the nuclear industry. Peace of mind with 10 year warranty and made in USA. Uses up to 90% less energy and can pay for itself in as little as 5 years from the energy savings. Cleans a larger area - up to 1,700 sq ft across multiple rooms on a floor. Simple controls with variable speed knob to dial in the exact air flow.