If you are looking for a compact and inexpensive radio that runs OpenTX, the TX12 from Radiomaster is your radio. At around two thirds the size of a traditional radio, with a removable antenna and folding carry handle, it's very compact and therefore an easy option to travel with. Despite it's smaller size, it's still comfortable to hold thanks to a well-designed casing, which incorporates handgrips.
Ideally suited to radio sailing, the radio carries various switches programmable through OpenTX for you to setup your own sheet adjustment and other features to get your around the course.
The multi-protocol T12 supports Futaba S-FHSS, Frsky D16/D8 (LBT or FCC) amongst others that are regularly used by radio sailors and for the real radio enthusiast, there is a JR-Style external module bay in the back of the radio which has the capability to support further protocols, such as TBS Crossfire.
Another great feature of this radio is its built-in charger. Simply connect to a USB source using the included cable - the status LED goes red to indicate charging, and goes off when it's complete. The USB port can also be used for data transfer with the Companion software, and for controlling a sim.
Please Note: 18650 Batteries and SD Card are NOT included.