Maximize the life out of any Airmax SilentAir Diaphragm Compressor by replacing the air filters on a regular basis. The durable filter media inside the LR25 and LR50 aeration compressors keep things cool by protecting the unit from contaminates and other debris. For longevity and maximum system performance, we recommend keeping the air filter clean and replacing it once every 3-6 months. Each package includes two replacement air filters. Compatible with Airmax Shallow Water Series Systems.