Ballast connectors--quick question

[Charlie587]

Guys,

I have a question for you all.

I noticed two connectors and a small black rubber "thingy" on my ballast.

I understand that one of the connector is for my power. However, I am completely lost on the other connector and that black rubber "thingy."


Please take a look at the attached picture.

The black rubber thingy is in red.
The "mysterious" connector is in blue.


Thanx

[Charlie587]

come on guys, I know it is a stupid question but can you please help out if you can =)