This is an internal TX module upgrade kit for your T16 radio. It will free up your external module bay so that you can use something like a crossfire module. Special promo price, limited time offer.
If you have an early version of the internal module and the firmware version is showing below 22.214.171.124 then you will need to update the module to have the bootloader installed so it will automatically get updated whenever you update opentx on the radio. See this link for complete tutorial on the flashing process and whats needed. If you have 126.96.36.199 or newer firmware on the module then this is not necessary.