The GCRGI GPS Antenna by Allis Communications is a reliable, high-performing antenna used with Iridium satellite phones for seamless communications and GPS position. A low profile passive/active antenna guarantees continuous signal coverage for excellent operation. Also know as the Alliscom Iridium + GPS Antenna, this antenna is easily installed and used by Crew on a steamer, the Navy along coastlines, and in desert caravans in need of GPS.