Product Description Reviews Product Description Minimum Efficiency Reporting Value: 8 Each filter lasts up to 3 months. Electrostatic charge captures airborne allergens SMALLER THAN 1 micron including fine dust, smoke, dander, mold, pet dander and dust mites. Also traps most large allergens including pollen and lint. Up to 20-times more effective at capturing micro particles than ordinary fiberglass filters. Designed for uniform air flow. Will not support the growth of bacteria, mold, mildew or fungi in normal use. 3 Reviews Hide Reviews Show Reviews 5 HVAC Filter Posted by Janice Barfield Fowler on Nov 19th 2021 We ordered the wrong size for a relative. When credit is provided, we need 20x30 - not 30 x 30. 5 Correct item Posted by Frank Jenkins on Dec 25th 2020 The correct item arrived and was the size ordered. 5 Filters were hard to find. Posted by Frank Jenkins on Dec 5th 2020 They were the perfect size for our air handler. They arrived in a short time. I am about to order filters for our other unit.