The Genuine Patriot® Motor Filter has two special features; it contains both an Activated Carbon and Reticulated Foam.  The activated carbon takes out most odors that come through the machine and the reticulated foam protects the motor from debris.  When changed properly (every 6 months to a year) you can help extend the life of your motor. *Note: over time dust, dirt, and debris can cause severe harm to the motor if this filter is not change regularly.