The GA38 GPS GLONASS Antenna is built to take advantage of the GLONASS system/constellation of satellites as well as standard GPs. This robust external antenna is packaged in a low-profile waterproof housing and provides 3 easy mounting solutions: pole, surface or under-deck (for the underside of fiberglass decks). External GPS/GLONASS antennas provide increased flexibility and installation options as well as the potential for enhanced reception of GPS/GLONASS signal for those products with built-in GPS/GLONASS antennas. Package Content: GA38surface mounting bracketpole mounting bracketudner-deck mounting bracketmounting hardwareantenna cable (231ftl/10m)installation instructionswarranty Attach it to a standard 1 inch OD, 14 threads per inch, pipe threaded pole (not included) Uses a BNC connector to connect to the port labeled ANTENNA or EXT GPS on a compatible chartplotter Fits Garmin 400, 500 series chartplotters and many earlier models as well Antenna cable (32 ft./10 m) Height 6.00 Width 6.00 Depth 6.00 Weight 1.88 Color Operating System Batteries Included Batteries Required Number of Batteries Battery Type No battery required Language English Assembly Required