TomTom External Antenna for GO 510 and 910 and ONE Navigators (9N00.000) (Discontinued by Manufacturer) External antenna for your TomTom ONE or TomTom GO 510 or 910 navigators Overcomes athermic heat-reflecting windshields and built-in windshield heaters that block GPS reception Magnetic GPS antenna makes it a snap to quickly place inside or outside your car Requires no difficult or permanent installation