Air purifiers with HEPA filters have the ability to remove up to 99.97% of particles as small as 0.3 microns, and the RpI-6Hepa is the replacement HEPA filter for the Airpura I-600 air purifier. This replacement filter features over 100 square feet of filtration surface with 3� deep folds, and is warm rolled to avoid cracking. Be sure to replace the HEPA filter in your I-600 every 5 years to maintain its efficiency.