The pre - filter can extend the service life of the filters for particles in the TR - 600 series trapping larger particles that can clog the filter. TR - 6600 pre - filter must be installed and used as shown in the instructions for use. It can reduce operating costs to extend the life of the filters in the TR - 600 series. TR - 6600 can be used with the spark arrester TR - 662. TR - 6600 does not require maintenance and must be disposed of if it binds or is damaged. The pre - filter can extend the service life of the filters for particles in the TR - 600 series trapping larger particles that can clog the filter. Frequently change the pre - filter can help optimize the performance of the system.