The Iridium GO! external antenna adapter is necessary to connect an external antenna to your Iridium GO! device.  This may be advantageous in situations where it is impossible to locate the Iridium GO! with a 360º view of the horizon while simultaneously within 100 feet of your Wi-Fi enabled smart phone or tablet. If your site is surrounded by tall trees, buildings or the superstructure of a ship, the view of the internal Iridium GO! antenna could be obstructed.