The Allergy Machine Jr. has a HEGA filter (High Efficiency Gas Absorption) surrounded by a True Medical HEPA filter, which means particles are captured first and then the HEGA filter can capture gases and odors. The inner filter (HEGA) was developed by the British military for use against chemical warfare and does not emit any particles. With 30 sq. ft. of medical HEPA, certified to remove 99.97 percent of airborne particles 0.3 microns and larger, once particles are captured they are permanently removed from the air for easier breathing. The powerful centrifugal fan maximizes air output while minimizing energy usage for pulling air through the filters, which means lower cost and faster room air purification (for rooms up to 700 sq. ft. with normal ceiling heights). Also available in white, sandstone, and black - see the HealthMate Jr. HEGA unit.