Filter King 19x23x1 Actual Size air filters are made to protect your homes accommodating air systems from incoming airborne particles. Air systems like HVACâ€s or furnaces need filters in place to keep the incoming airflow free of intruding particles. Our air filter consists of a tight mesh weaving that keeps airflow coming in and raises a homeâ€s indoor air quality. The air filter will stop a full range of irritants but become dirty in the process and require replacement. Dirty air filters are a problem for your home; you should replace them as soon as possible to avoid any issues. When your air filters are dirty, they are capable of causing a range of problems that only grow worse over time. Over time, the dirty air filters will cause an increase in billing and a strain on your air system. You will need new air filters installed to keep the airflow in your home traveling smoothly. Our premium air filters rank as an eight on the MERV (Minimum Efficiency Reporting Value) scale and can block out particles like pollen, dust, pet dander, & smoke.