I can't believe it took me this long to realize this...

['Awve Tìkameie]

I was resizing and cropping the picture below when I noticed the name tag on the top right of the picture, Jake's left ear:

Note: It's not a name tag, but a tag that says RDA on it. It is kind of like what the scientists use to track migrating patterns of animals

[Txon Taronyu]

when in the movie was that
Also it is probely just so the scinetist know were jack is and also in the movie they can see some of the stuff he does like when he first sees the tree of souls

so its a camera/ tracker probely

[Technowraith]

when in the movie was that

When Jake is firing at the Thanator. I thought it was just a marker to distinguish Avatars from real Na'vi. In a more obvious way, other than the physical differences.

[Panzerfaust]

Looks like part of his throat-mike setup to me... just a radio.

[Txontaw]

Looks like part of his throat-mike setup to me... just a radio.

Yeah, it goes along with the throat mike. How else do you think you would hear the people talking to you?

[Tsepxor]

Think of it as like a kind of bluetooth earpiece

['Awve Tìkameie]

Looks like part of his throat-mike setup to me... just a radio.

Yeah, it goes along with the throat mike. How else do you think you would hear the people talking to you?

I agree. Look at these two pictures, the first two is when Jake is at the Ikran Rookery, picking his Ikran. The nest two is when he is on his Great Leonopteryx aka Toruk.

[Will Txankamuse]

Jakesully goes back to the module/samson and picks up throat mics and headsets for Tsu'tey, Neytiri, Norm and himself.  This is what they use to communicate throughout the battle.  Jakesully loses his first set when he jumps into the water escaping the thanator.

Will

['Awve Tìkameie]

Jakesully goes back to the module/samson and picks up throat mics and headsets for Tsu'tey, Neytiri, Norm and himself.  This is what they use to communicate throughout the battle.  Jakesully loses his first set when he jumps into the water escaping the thanator.

Will

Oh, ok. I didn't notice that part in the movie. But it makes sence.

[kintìomum]

It's not shown that Jake goes back to get the transceivers for the final battle but it's the most likely source for Jake to get new sets.

What opens another question to me: Why don't the RDA monitor their frequencies? With that much space in the Dragon and the use as a mobile C³-Center in the assault it's either stupidity or lack of awareness that they don't pick up transmissions that are made with one of the sets that's been produced in their factory, working on their frequencies and that was issued to a lab that's gone rogue...

[Will Txankamuse]

It's not shown that Jake goes back to get the transceivers for the final battle but it's the most likely source for Jake to get new sets.

this is true, I should have said it was speculation - but it makes sense that jakesully either obtained the mics from either the samson or the module in the intervening part while the Na'vi were preparing for the battle.

What opens another question to me: Why don't the RDA monitor their frequencies? With that much space in the Dragon and the use as a mobile C³-Center in the assault it's either stupidity or lack of awareness that they don't pick up transmissions that are made with one of the sets that's been produced in their factory, working on their frequencies and that was issued to a lab that's gone rogue...

This is a very good point, I doubt they had the facilities to recode the frequencies away from the main base.  I expect the humans just never guessed they would be using the headsets and didn't bother scanning the extra frequencies.  Cameron undoubtedly wanted the ability for them to communicate - especially for the scene where Jakesully tells Neytiri not to fight RDA in the dramatic 'Eywa has heard you' scene, but didn't have time for an extra scene where they changed frequencies.

Will

[Technowraith]

It's not shown that Jake goes back to get the transceivers for the final battle but it's the most likely source for Jake to get new sets.

What opens another question to me: Why don't the RDA monitor their frequencies? With that much space in the Dragon and the use as a mobile C³-Center in the assault it's either stupidity or lack of awareness that they don't pick up transmissions that are made with one of the sets that's been produced in their factory, working on their frequencies and that was issued to a lab that's gone rogue...

It wouldn't surprise  me if the scientific crews had their own set of radios. Makes sense to have them really. And those radios may operate on different frequencies. So it would be entirely possible to have radio traffic on a different channel and not realize it. It would also seem odd that in the case of RDA, they would consider monitoring radio traffic. But then again, their mindset may have been: screw monitoring radio traffic cuz we're gonna kick their collective butts and win. So why bother?

[Txontaw]

It's not shown that Jake goes back to get the transceivers for the final battle but it's the most likely source for Jake to get new sets.

What opens another question to me: Why don't the RDA monitor their frequencies? With that much space in the Dragon and the use as a mobile C³-Center in the assault it's either stupidity or lack of awareness that they don't pick up transmissions that are made with one of the sets that's been produced in their factory, working on their frequencies and that was issued to a lab that's gone rogue...

It wouldn't surprise  me if the scientific crews had their own set of radios. Makes sense to have them really. And those radios may operate on different frequencies. So it would be entirely possible to have radio traffic on a different channel and not realize it. It would also seem odd that in the case of RDA, they would consider monitoring radio traffic. But then again, their mindset may have been: screw monitoring radio traffic cuz we're gonna kick their collective butts and win. So why bother?

I don't think they knew that they even had radios, so why would they monitor it?

[TorukMakto!]

Jakesully goes back to the module/samson and picks up throat mics and headsets for Tsu'tey, Neytiri, Norm and himself.  This is what they use to communicate throughout the battle.  Jakesully loses his first set when he jumps into the water escaping the thanator.

Will

I'd second that.
He probably also gave a brief explaination to Neytii and Tsu'tey of how to use the device before the final battle, there is a possibility that they might were familiar with this before hand at the tie when Grace used to visit and teach at their tribe, but I doubt it.