The Garmin GXM-51XM Satellite Weather Antenna provides XM satellite radio and XM WX satellite weather data to 2009 portrait chartplotters and NMEA 2000 compatible chartplotters. Powered directly from the NMEA 2000 bus rather than from a separate power connection. GXM-51XM Satellite Weather Antenna from Garmin uses the same convenient pole, flush, and under-deck mounts as the GPS 17X. Waterproof design meets IPX7 standards. Garmin GXM-51XM requires no black box purchase.