Review on No Toil Castle One Year Furnace Filtration for HVAC Filtration by James Nedumaran

To be honest, people who say it limits airflow have to take it on their heads. No wonder an arrow shows the direction of airflow. This is my second time buying these filters. I think they do a good job BUT I don't think they can last a full year. I change mine about every six months. I also think the time depends on where you live and the condition of your environment (smoking, pets, etc.). The only negative is the steep price for each.