Simply 20x20x1 Air Filter, Merv 8, MPR 600, 4 Pack, Furnace Air Filter for HVAC (Actual Size: 19.75″x19.75″x0.75″) DUST, Pet, & Allergy Control

Customers find these air filters to be of good quality and value for money, working effectively and fitting perfectly inside furnace entry points. The size receives mixed feedback - while some find them properly sized, others report they are 1/2" too short in both length and width. Installation experiences are also mixed, with some finding them easy to install while others report difficulties. Customers disagree on the filters' sturdiness, with some describing them as well-built while others find them flimsy. Similarly, opinions on airflow are divided, with some noting a marked difference in air quality while others mention they block proper airflow.