Hey guys i am a super noob.... But what is a module???? What does it do? ....... And do you know if i need it for this remote
http://www3.towerhobbies.com/cgi-bin...&I=LXZHF9&P=ML

What context are we speaking in? I assume you're talking about radio equipment... in that case a "module" is probably referring to the antenna unit that attaches to the transmitter and sends out the signal to the receiver (and in some cases receives telemetry information back). No, any radio I've seen - especially 2.4GHz - comes with a module with/in the transmitter. Most of the time they sell them as replacements in case it breaks, then you don't have to buy a whole new transmitter.

The purpose of the module on high end radios was to allow the use of different frequency bands (40Mhz FM, 27Mhz FM, 75mhz FM, 2.4Ghz, etc).

The MX-3X does not use a module and it is only compatible with other Airtronics 2.4Ghz receivers.

As an example - these are 'modules' that go with various Futaba radios - I use the FM, Synthesized FM and 2.4Ghz modules in my 3PK radio - provides great flexibility.

http://www3.towerhobbies.com/cgi-bin...%3C%2FB%3Eules