Plug these Amimon Cable Antennas into your CONNEX Air Unit transmitter to ensure proper communication between the Air and Ground Units. These are Tx antennas (as opposed to RX), meaning they are designated as transmission antennas. Once the cables are plugged into your Air Unit, use the Amimon Cable Mounting Plate (sold separately) to install the antennas onto your aircraft. Both of these antennas must be plugged into the transmitter and installed vertically on your aircraft to ensure your Air Unit functions and communicates properly. Each antenna is 19.7' (50.0 cm) long.