It is a magical bug, that will allow the owner to hear what is said in the immediate vicinity of the “bug.”
Once two or more matching helms are found and worn, they enable the individuals to communicate like they were standing next to each other. The helms transmit all sounds including the surrounding noise and at the same volume as the original.
Itching dust makes someone or something itch. It is very distracting and only gets worse until the dust wears out or an antidote is applied.
Wearer of this shirt can walk unnoticed into almost any even/gathering/bank and perform just about any action without being noticed. Only extremely out-of-place action will get the wearer noticed at all.
Real World: some Indians in the Amazon treat their eyes with a traditional potion applied with palm leaves. Brutally painful, the drug alters vision, giving the jungle's dense green walls greater texture and dimension. You could adapt this to desert or swamps, or other hard to navigate regions.