DESC: Peaceful Breeze™ Model 688 medium room air purifier uses a combination of filtration processes to provide you with a HEPA filter air purifier, an activated carbon filter air purifier and/or an ionic air purifier all in one unit. The negative-ion generator, sponge pre-filter, HEPA filter, activated carbon filter and multi-catalyst filter combine to eliminate and absorb household odors, smoke, germs and harmful gases.