The all-new and improved PreMax pre-filter is the beginning of the new standard for high-performance air purification brought to you by IQAir. The pre-filter eliminates coarse and fine particles like dust, pollen, mold spores and more. It"s 99% efficient to 5 microns, which extends the life of the HyperHEPA filter. Although the new PreMax pre-filter (designed for all IQAir New Edition and previous-generation HealthPro systems) is improved over the previous generation, it doesn"t look any different. That"s because it was re-engineered on the inside not the outside. What IQAir designers and engineers did was perfect the pleating and reduce the weight of the separators. All with the goal of offering more clean air and longer filter life. It"s the kind of change you"ll notice-by not noticing it. So although the new PreMax pre-filter looks the same, it"s lighter than the original and provides more active surface area and more even filter loading. And it"s longer lasting than the previous generation, too. So you get up to 25% more clean air and spend up to 20% less on filter replacement costs. The PreMax pre-filter and the HyperHEPA filter are great examples of how IQAir filters work together to give you the best filtration possible.