Revolution Transmitters Overview: I use the term transmitter because it is how most people describe the unit, but the Revolution system is really 2 way communication. There is a limited amount of information coming back from the decoder/receiver, but indeed it is 2 way. This page is mostly on the transmitter/throttle. I will go into detailed descriptions on the receiver/decoder pages. First units: The very first units had a plastic keyboard, and also a charging jack on the bottom. These units were mainly beta test units, given away, or sold at a deep discount. There are not many of these still out there as I understand. Current units: Rubberized keys and a collar on the "antenna" nub so the case does not split apart when dropped. (True) Firmware versions: (list versions, what is missing or fixed) Updating / re-downloading firmware: describe USB dongle, procedure