This add-on board is designed for the Flysky 2.4Ghz 9-channel radio transmitter model FS-TH9B, commonly referred to as the "9x". It is also sold under various other re-branded model names, including (but not limited to): Flysky FS-TH9X, Eurgle 2.4Ghz, iMax 9x, and Turnigy 9x.

The 9x is an amazing value in the r/c aircraft world. You won't find a radio that costs so little that can do so much! However, it is not without its limitations. The primary complaint is that the stock firmware is quite poor. Thankfully, some very clever people (incl NZer) have written entirely new open source firmware that makes this cheap radio so powerful and flexible that it does things that units costing several hundreds of dollars more can't even dream of doing! This add-on board lets you load that new firmware onto your radio easily - with no soldering, cutting, specialized tools or skills required! As a bonus, it also provides advanced support for the popular Hobby King 9x LED backlight system (some soldering required for this optional feature).

The primary feature of the board is that it gives you a full-time programmer installed in your radio that allows you to "flash" for free the latest new improved firmware onto your radio whenever you want, just by plugging it into your PC via a common mini USB cable (not included). NB substantially upgraded version of ER9x is being released.

The second feature is the integrated LED backlight driver, which provides support circuitry for the popular - and inexpensive - HobbyKing LED backlight (not included). The circuitry adds the ability (once appropriate firmware has been flashed) to turn the backlight on and off by a variety of methods, and also provides full control over brightness.

Thirdly you can connect for free (try them even if you do not own the transmitter) to Eepe (for the er9x project) and Companion9x (for the OpenTX project) to load and save unlimited models to a computer or program models on the computer.

Complete with installation pdf guide.