looking for hermetically sealed button

[[email protected]]

If you recognize this button and knows where to buy it, please email
[email protected]. We will pay $20 for the first correct answer.
These buttons are hermetically sealed, about the size of a quarter and
ultra-flat.
Picture of button at:
http://tiagao.googlepages.com/

 

[Homer J Simpson]

If you recognize this button and knows where to buy it, please email
[email protected]. We will pay $20 for the first correct answer.
These buttons are hermetically sealed, about the size of a quarter and
ultra-flat.
Picture of button at:
http://tiagao.googlepages.com/

What do they do?