In order to ensure proper installation and certification of specific Garmin panel-mounted products, Garmin requires Garmin distributors to personally install every new listed product they sell. These products include the GNS-430, GNS-530, GNC-420, GPS-400, GNC-300XL, GPS-155XL, GPS-165, GMA-340, and GTX-327. There are only two exceptions to this distributor installation only policy. First, a distributor may sell the aforementioned equipment for amateur built/kitplane customers provided that this equipment is sold as part of an entire panel, with all interfacing between systems and bench testing completed by the Garmin distributor. Second, a distributor may sell the aforementioned equipment direct to another Garmin distributor.