You can help us keep FlightAware free by allowing ads from FlightAware.com. We work hard to keep our advertising relevant and unobtrusive to create a great experience. It's quick and easy to
whitelist ads on FlightAware or please consider our
premium accounts.
https://buy.garmin.com/en-US/US/in-the-air/general-aviation/transponders/gtx-335/prod140939.html
https://buy.garmin.com/en-US/US/in-the-air/general-aviation/transponders/gtx-345/prod140949.html
The dual band model with bluetooth support is of course the more expensive one...