From the Federal Register:

The FAA has determined that two manufacturers with products containing 60% or more U.S. content and U.S. final assembly are able to produce sufficient and reasonable amounts of FOD detection equipment meeting the requirements of FAA Advisory Circular 150/5220-24. Subsequently, the FAA will issue Buy American Waivers based on the 60% U.S. content and U.S. final assembly. The FAA will not issue any Buy American Waivers based on insufficient quantity to foreign manufacturers.

As a result the FAA will issue a Nationwide Buy American Waiver for the Trex Aviation Systems’ FOD Finder XF* and QinetiQ’s Tarsier FOD System based on the 60% U.S. content and U.S. final assembly waiver permitted in 49 U.S.C. 50101(b)(3). With the presence of these two manufacturers in the United States the FAA has determined there is sufficient quantity and consequently there is no justification for issuing any Buy American Waivers to foreign manufacturers based on insufficient quantity at this time.

This “Nationwide Waiver” will allow Trex Aviation Systems’ FOD Finder XF* and QinetiQ’s Tarsier FOD System to be used on AIP funded projects without having to receive separate waivers for each project. Having a nationwide waiver enables projects to start quickly without having to wait for the Buy American analysis to be completed for every project, while still assuring the funds used for airport projects under the statute are being directed to manufacturers that meet the Buy American requirements.

*The FOD Finder XF is Trex’s fixed solution, Trex is better known for their mobile solution, the FOD Finder XM.

Source (the federal register)(PDF version)