A2P filter for the fan motor 3M™ Versaflo™ series TR - 600 easy to install 3M recommends the use of TR - 6100FC filter cover to help protect the filter from physical damage. A2P filter for the 3M™ Versaflo™ series TR - 600 fan motor filter is directly coupled to the fan motor. 3m recommends the use of the TR - 6300FC filter cover to help protect the filter from physical damage. TR - 6300FC filter cover is also used to keep the pre - filter TR - 6600 or the TR - 662 spark arrester on your website.