The standard ST16 controller has two external antennas. These antennas are responsible for the communication between the ST16 controller, and the CGO3+ camera and Typhoon H. There are two other antennas that are internal. These two antennas are for the wi-fi and telemetry. The ST16+ has the same four antennas; the difference is that the telemetry antenna is external as well, adding up to be 3 total external antennas. The other difference between the two controllers is the antennas used for the CGO3+ signal. The standard ST16 uses a mushroom antenna, while the ST16+ uses a more reliable patch antenna. This kit includes the parts that you need to upgrade your standard ST16 to a ST16+. It includes: 1 patch antenna, 1 whip antenna, and 1 antenna connection wire. 

Thanks for looking!

Sold by Authorized Yuneec Dealer, Terrestrial Imaging 

Note: This item is not returnable once the package is opened.