Surround Air S5000PH TI02 Filter - About Surround Air A division of Indoor Purification Systems, Inc., Surround Air, has been providing breathability and purification to the environments you occupy since 1998. They're proud to provide air purifiers and humidifiers of all sizes and price ranges that incorporate the latest and most reliable technologies and materials. Advanced true HEPA filters, germ-killing technologies, odor-eliminating carbon filters, built-in ionization, air sanitization, photocatalytic filters, and many more advanced techniques go into Surround Air products, so that only clean air comes out. They also make and distribute low-cost and high efficiency replacement filters and parts for all their equipment, so It's easy to keep it green and clean. Invite Surround Air into your home or business and breathe easy. S series spare photo catalytic designed filter. Transforms VOC's in water and carbon dioxide molecules. Stops airborne bacteria. Filters need to be replaced every year for best result.