Use the GA 30 as an external antenna for devices with an internal GPS antenna, when mounting the display in a below-deck location. The robust and passive GA 30 GPS antenna is packaged in a low-profile waterproof housing and provides three easy mounting solutions: pole mount, surface mount or under-deck mount (for the underside of fiberglass decks). Compatible with the full line of 400/500/700 Series plotters and fishfinder-plotter combos as well as the GPSMAP 640 and Garmin handhelds. Includes surface, pole and under-deck mounting brackets, mounting hardware, installation instructions. Dimensions: 3 19/32″ dia. x 1 15/16″H. Weight: 7.1oz. Waterproof rating: IPX7 submersibleIncludes surface, pole and under-deck mounting brackets, mounting hardware, antenna cable (32 ft/10 m) and installation instructions.