These filters fit my high efficiency furnace perfectly putting an end to my struggles with the cheap filters I was buying at the home improvement stores.
I change my furnace filter every three months. I have allergies and I want my air as clean as possible. My HVAC guy has warned me about using too high of a MERV value due to the potential of restricting airflow which has the potential to damage the system. I like that these have the feature of not restricting airflow. Very easy to use.