The Iridium GO!™ antenna adapter cable connects to an Iridium antenna (sold separately) and theIridium GO! device. It provides TS9 (Iridium GO!) to TNC-F (Iridium Antenna) connector with 15cm length. Plug in to the Iridium GO! external antenna port with a smaller TS9 connector, then connect the Iridium Antenna with the larger TNC-F connector.