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Maintaining the M120 Air Filter



For optimum cooling, verify the condition of the air filters.


  • A dirty air filter restricts airflow in the unit, producing a negative effect on the ventilation of the chassis. The filter elements degrade over time, so the filter elements in use, should be replaced every 6 months. For procedures to replace the air filter, see Replacing an M120 Air Filter.

  • Spare filter elements should be used within one year of manufacture. Check the date of manufacture printed on the filter. Store spare filter elements in a dark, cool, and dry place. Storing the filter elements at higher temperatures, or where they can be exposed to ultraviolet (UV) radiation, hydrocarbon emissions, or vapors from solvents, can significantly reduce their life.


Always keep the air filter in place while the router is operating. Because the fans are very powerful, they could pull small bits of wire or other materials into the router through the unfiltered air intake. This could damage the router components.